#pragma comment(linker, "/STACK:36777216")
//#pragma GCC optimize ("O2")
/**
 *    This code has been written by YueGuang, feel free to ask me question. Blog: http://www.moonl1ght.xyz
 *    created:
 */
#define LOCAL
#include <functional>
#include <algorithm>
#include <iostream>
#include <fstream>
#include <sstream>
#include <iomanip>
#include <numeric>
#include <cstring>
#include <climits>
#include <cassert>
#include <complex>
#include <cstdio>
#include <string>
#include <vector>
#include <bitset>
#include <queue>
#include <stack>
#include <cmath>
#include <ctime>
#include <list>
#include <set>
#include <map>

//#include <tr1/unordered_set>
//#include <tr1/unordered_map>
//#include <array>

using namespace std;

#define REP(i, n) for (int i=0;i<n;++i)
#define FOR(i, a, b) for (int i=a;i<b;++i)
#define DWN(i, b, a) for (int i=b-1;i>=a;--i)
#define REP_1(i, n) for (int i=1;i<=n;++i)
#define FOR_1(i, a, b) for (int i=a;i<=b;++i)
#define DWN_1(i, b, a) for (int i=b;i>=a;--i)
#define REP_C(i, n) for (int n____=n,i=0;i<n____;++i)
#define FOR_C(i, a, b) for (int b____=b,i=a;i<b____;++i)
#define DWN_C(i, b, a) for (int a____=a,i=b-1;i>=a____;--i)
#define REP_N(i, n) for (i=0;i<n;++i)
#define FOR_N(i, a, b) for (i=a;i<b;++i)
#define DWN_N(i, b, a) for (i=b-1;i>=a;--i)
#define REP_1_C(i, n) for (int n____=n,i=1;i<=n____;++i)
#define FOR_1_C(i, a, b) for (int b____=b,i=a;i<=b____;++i)
#define DWN_1_C(i, b, a) for (int a____=a,i=b;i>=a____;--i)
#define REP_1_N(i, n) for (i=1;i<=n;++i)
#define FOR_1_N(i, a, b) for (i=a;i<=b;++i)
#define DWN_1_N(i, b, a) for (i=b;i>=a;--i)
#define REP_C_N(i, n) for (int n____=(i=0,n);i<n____;++i)
#define FOR_C_N(i, a, b) for (int b____=(i=0,b);i<b____;++i)
#define DWN_C_N(i, b, a) for (int a____=(i=b-1,a);i>=a____;--i)
#define REP_1_C_N(i, n) for (int n____=(i=1,n);i<=n____;++i)
#define FOR_1_C_N(i, a, b) for (int b____=(i=a,b);i<=b____;++i)
#define DWN_1_C_N(i, b, a) for (int a____=(i=b,a);i>=a____;--i)

#define ECH(it, A) for (__typeof((A).begin()) it=(A).begin(); it != (A).end(); ++it)
#define rECH(it, A) for (__typeof((A).rbegin()) it=(A).rbegin(); it != (A).rend(); ++it)
#define REP_S(i, str) for (char*i=str;*i;++i)
#define REP_L(i, hd, suc) for (int i=hd;i;i=suc[i])
#define REP_G(i, u) REP_L(i,hd[u],suc)
#define REP_SS(x, s) for (int x=s;x;x=(x-1)&s)
#define DO(n) for ( int ____n = n; ____n-->0; )
#define REP_2(i, j, n, m) REP(i, n) REP(j, m)
#define REP_2_1(i, j, n, m) REP_1(i, n) REP_1(j, m)
#define REP_3(i, j, k, n, m, l) REP(i, n) REP(j, m) REP(k, l)
#define REP_3_1(i, j, k, n, m, l) REP_1(i, n) REP_1(j, m) REP_1(k, l)
#define REP_4(i, j, k, ii, n, m, l, nn) REP(i, n) REP(j, m) REP(k, l) REP(ii, nn)
#define REP_4_1(i, j, k, ii, n, m, l, nn) REP_1(i, n) REP_1(j, m) REP_1(k, l) REP_1(ii, nn)

#define ALL(A) A.begin(), A.end()
#define LLA(A) A.rbegin(), A.rend()
#define CPY(A, B) memcpy(A, B, sizeof(A))
#define INS(A, P, B) A.insert(A.begin() + P, B)
#define ERS(A, P) A.erase(A.begin() + P)
#define LBD(A, x) (lower_bound(ALL(A), x) - A.begin())
#define UBD(A, x) (upper_bound(ALL(A), x) - A.begin())
#define CTN(T, x) (T.find(x) != T.end())
#define SZ(A) int((A).size())
#define PB push_back
#define MP(A, B) make_pair(A, B)
#define PTT pair<T, T>
#define Ts *this
#define rTs return Ts
#define fi first
#define se second
#define re real()
#define im imag()

#define Rush for(int ____T=RD(); ____T--;)
#define Display(A, n, m) {                      \
REP(i, n){                                    \
REP(j, m-1) cout << A[i][j] << " ";     \
cout << A[i][m-1] << endl;                \
}                                            \
}
#define Display_1(A, n, m) {                    \
REP_1(i, n){                                \
REP_1(j, m-1) cout << A[i][j] << " ";   \
cout << A[i][m] << endl;                \
}                                            \
}

typedef long long LL;
//typedef long double DB;
typedef double DB;
typedef unsigned uint;
typedef unsigned long long uLL;

typedef vector<int> VI;
typedef vector<char> VC;
typedef vector<string> VS;
typedef vector<LL> VL;
typedef vector<DB> VF;
typedef set<int> SI;
typedef set<string> SS;
typedef map<int, int> MII;
typedef map<string, int> MSI;
typedef pair<int, int> PII;
typedef pair<LL, LL> PLL;
typedef vector<PII> VII;
typedef vector<VI> VVI;
typedef vector<VII> VVII;

template<class T> inline T& RD(T &);
template<class T> inline void OT(const T &);
//inline int RD(){int x; return RD(x);}
inline LL RD(){LL x; return RD(x);}
inline DB& RF(DB &);
inline DB RF(){DB x; return RF(x);}
inline char* RS(char *s);
inline char& RC(char &c);
inline char RC();
inline char& RC(char &c){scanf(" %c", &c); return c;}
inline char RC(){char c; return RC(c);}
//inline char& RC(char &c){c = getchar(); return c;}
//inline char RC(){return getchar();}

template<class T> inline T& RDD(T &);
inline LL RDD(){LL x; return RDD(x);}

template<class T0, class T1> inline T0& RD(T0 &x0, T1 &x1){RD(x0), RD(x1); return x0;}
template<class T0, class T1, class T2> inline T0& RD(T0 &x0, T1 &x1, T2 &x2){RD(x0), RD(x1), RD(x2); return x0;}
template<class T0, class T1, class T2, class T3> inline T0& RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3){RD(x0), RD(x1), RD(x2), RD(x3); return x0;}
template<class T0, class T1, class T2, class T3, class T4> inline T0& RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4){RD(x0), RD(x1), RD(x2), RD(x3), RD(x4); return x0;}
template<class T0, class T1, class T2, class T3, class T4, class T5> inline T0& RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4, T5 &x5){RD(x0), RD(x1), RD(x2), RD(x3), RD(x4), RD(x5); return x0;}
template<class T0, class T1, class T2, class T3, class T4, class T5, class T6> inline T0& RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4, T5 &x5, T6 &x6){RD(x0), RD(x1), RD(x2), RD(x3), RD(x4), RD(x5), RD(x6); return x0;}
template<class T0, class T1> inline void OT(const T0 &x0, const T1 &x1){OT(x0), OT(x1);}
template<class T0, class T1, class T2> inline void OT(const T0 &x0, const T1 &x1, const T2 &x2){OT(x0), OT(x1), OT(x2);}
template<class T0, class T1, class T2, class T3> inline void OT(const T0 &x0, const T1 &x1, const T2 &x2, const T3 &x3){OT(x0), OT(x1), OT(x2), OT(x3);}
template<class T0, class T1, class T2, class T3, class T4> inline void OT(const T0 &x0, const T1 &x1, const T2 &x2, const T3 &x3, const T4 &x4){OT(x0), OT(x1), OT(x2), OT(x3), OT(x4);}
template<class T0, class T1, class T2, class T3, class T4, class T5> inline void OT(const T0 &x0, const T1 &x1, const T2 &x2, const T3 &x3, const T4 &x4, const T5 &x5){OT(x0), OT(x1), OT(x2), OT(x3), OT(x4), OT(x5);}
template<class T0, class T1, class T2, class T3, class T4, class T5, class T6> inline void OT(const T0 &x0, const T1 &x1, const T2 &x2, const T3 &x3, const T4 &x4, const T5 &x5, const T6 &x6){OT(x0), OT(x1), OT(x2), OT(x3), OT(x4), OT(x5), OT(x6);}
inline char& RC(char &a, char &b){RC(a), RC(b); return a;}
inline char& RC(char &a, char &b, char &c){RC(a), RC(b), RC(c); return a;}
inline char& RC(char &a, char &b, char &c, char &d){RC(a), RC(b), RC(c), RC(d); return a;}
inline char& RC(char &a, char &b, char &c, char &d, char &e){RC(a), RC(b), RC(c), RC(d), RC(e); return a;}
inline char& RC(char &a, char &b, char &c, char &d, char &e, char &f){RC(a), RC(b), RC(c), RC(d), RC(e), RC(f); return a;}
inline char& RC(char &a, char &b, char &c, char &d, char &e, char &f, char &g){RC(a), RC(b), RC(c), RC(d), RC(e), RC(f), RC(g); return a;}
inline DB& RF(DB &a, DB &b){RF(a), RF(b); return a;}
inline DB& RF(DB &a, DB &b, DB &c){RF(a), RF(b), RF(c); return a;}
inline DB& RF(DB &a, DB &b, DB &c, DB &d){RF(a), RF(b), RF(c), RF(d); return a;}
inline DB& RF(DB &a, DB &b, DB &c, DB &d, DB &e){RF(a), RF(b), RF(c), RF(d), RF(e); return a;}
inline DB& RF(DB &a, DB &b, DB &c, DB &d, DB &e, DB &f){RF(a), RF(b), RF(c), RF(d), RF(e), RF(f); return a;}
inline DB& RF(DB &a, DB &b, DB &c, DB &d, DB &e, DB &f, DB &g){RF(a), RF(b), RF(c), RF(d), RF(e), RF(f), RF(g); return a;}
inline void RS(char *s1, char *s2){RS(s1), RS(s2);}
inline void RS(char *s1, char *s2, char *s3){RS(s1), RS(s2), RS(s3);}
template<class T0,class T1>inline T0& RDD(T0&a, T1&b){RDD(a),RDD(b); return a;}
template<class T0,class T1,class T2>inline T1& RDD(T0&a, T1&b, T2&c){RDD(a),RDD(b),RDD(c); return a;}

template<class T> inline void RST(T &A){memset(A, 0, sizeof(A));}
template<class T> inline void FLC(T &A, int x){memset(A, x, sizeof(A));}
template<class T> inline void CLR(T &A){A.clear();}

template<class T0, class T1> inline void RST(T0 &A0, T1 &A1){RST(A0), RST(A1);}
template<class T0, class T1, class T2> inline void RST(T0 &A0, T1 &A1, T2 &A2){RST(A0), RST(A1), RST(A2);}
template<class T0, class T1, class T2, class T3> inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3){RST(A0), RST(A1), RST(A2), RST(A3);}
template<class T0, class T1, class T2, class T3, class T4> inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4){RST(A0), RST(A1), RST(A2), RST(A3), RST(A4);}
template<class T0, class T1, class T2, class T3, class T4, class T5> inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5){RST(A0), RST(A1), RST(A2), RST(A3), RST(A4), RST(A5);}
template<class T0, class T1, class T2, class T3, class T4, class T5, class T6> inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5, T6 &A6){RST(A0), RST(A1), RST(A2), RST(A3), RST(A4), RST(A5), RST(A6);}
template<class T0, class T1> inline void FLC(T0 &A0, T1 &A1, int x){FLC(A0, x), FLC(A1, x);}
template<class T0, class T1, class T2> inline void FLC(T0 &A0, T1 &A1, T2 &A2, int x){FLC(A0, x), FLC(A1, x), FLC(A2, x);}
template<class T0, class T1, class T2, class T3> inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3, int x){FLC(A0, x), FLC(A1, x), FLC(A2, x), FLC(A3, x);}
template<class T0, class T1, class T2, class T3, class T4> inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, int x){FLC(A0, x), FLC(A1, x), FLC(A2, x), FLC(A3, x), FLC(A4, x);}
template<class T0, class T1, class T2, class T3, class T4, class T5> inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5, int x){FLC(A0, x), FLC(A1, x), FLC(A2, x), FLC(A3, x), FLC(A4, x), FLC(A5, x);}
template<class T0, class T1, class T2, class T3, class T4, class T5, class T6> inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5, T6 &A6, int x){FLC(A0, x), FLC(A1, x), FLC(A2, x), FLC(A3, x), FLC(A4, x), FLC(A5, x), FLC(A6, x);}
template<class T> inline void CLR(priority_queue<T, vector<T>, less<T> > &Q){while (!Q.empty()) Q.pop();}
template<class T> inline void CLR(priority_queue<T, vector<T>, greater<T> > &Q){while (!Q.empty()) Q.pop();}
template<class T> inline void CLR(stack<T> &S){while (!S.empty()) S.pop();}
template<class T> inline void CLR(queue<T> &Q){while (!Q.empty()) Q.pop();}

template<class T0, class T1> inline void CLR(T0 &A0, T1 &A1){CLR(A0), CLR(A1);}
template<class T0, class T1, class T2> inline void CLR(T0 &A0, T1 &A1, T2 &A2){CLR(A0), CLR(A1), CLR(A2);}
template<class T0, class T1, class T2, class T3> inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3){CLR(A0), CLR(A1), CLR(A2), CLR(A3);}
template<class T0, class T1, class T2, class T3, class T4> inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4){CLR(A0), CLR(A1), CLR(A2), CLR(A3), CLR(A4);}
template<class T0, class T1, class T2, class T3, class T4, class T5> inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5){CLR(A0), CLR(A1), CLR(A2), CLR(A3), CLR(A4), CLR(A5);}
template<class T0, class T1, class T2, class T3, class T4, class T5, class T6> inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5, T6 &A6){CLR(A0), CLR(A1), CLR(A2), CLR(A3), CLR(A4), CLR(A5), CLR(A6);}
template<class T> inline void CLR(T &A, int n){REP(i, n) CLR(A[i]);}

template<class T> inline bool EPT(T &a){return a.empty();}
template<class T> inline T& SRT(T &A){sort(ALL(A)); return A;}
template<class T, class C> inline T& SRT(T &A, C cmp){sort(ALL(A), cmp); return A;}
template<class T> inline T& RVS(T &A){reverse(ALL(A)); return A;}
template<class T> inline T& UNQQ(T &A){A.resize(unique(ALL(A))-A.begin());return A;}
template<class T> inline T& UNQ(T &A){SRT(A);return UNQQ(A);}
template<class T, class C> inline T& UNQ(T &A, C cmp){SRT(A, cmp);return UNQQ(A);}

//}

/** Constant List .. **/ //{

const int MOD = int(1e9) + 7;
const int INF = 0x3f3f3f3f;
const LL INFF = 0x3f3f3f3f3f3f3f3fLL;
const DB EPS = 1e-9;
const DB OO = 1e20;
const DB PI = acos(-1.0); //M_PI;

const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, 1, 0, -1};

//}

/** Add On .. **/ //{
// <<= '0. Nichi Joo ., //{

template<class T> inline bool checkMin(T &a,const T b){return b < a ? a = b, 1 : 0;}
template<class T> inline bool checkMax(T &a,const T b){return a < b ? a = b, 1 : 0;}
template <class T, class C> inline bool checkUpd(T& a, const T b, C c){return c(b,a) ? a = b, 1 : 0;}
template<class T> inline T min(T a, T b, T c){return min(min(a, b), c);}
template<class T> inline T max(T a, T b, T c){return max(max(a, b), c);}
template<class T> inline T min(T a, T b, T c, T d){return min(min(a, b), min(c, d));}
template<class T> inline T max(T a, T b, T c, T d){return max(max(a, b), max(c, d));}
template<class T> inline T min(T a, T b, T c, T d, T e){return min(min(min(a,b),min(c,d)),e);}
template<class T> inline T max(T a, T b, T c, T d, T e){return max(max(max(a,b),max(c,d)),e);}
template<class T> inline T sqr(T a){return a*a;}
template<class T> inline T cub(T a){return a*a*a;}
template<class T> inline T ceil(T x, T y){return (x - 1) / y + 1;}
template<class T> T abs(T x){return x>0?x:-x;}
inline int sgn(DB x){return x < -EPS ? -1 : x > EPS;}
inline int sgn(DB x, DB y){return sgn(x - y);}

inline DB cos(DB a, DB b, DB c){return (sqr(a)+sqr(b)-sqr(c))/(2*a*b);}
inline DB cot(DB x){return 1./tan(x);};
inline DB sec(DB x){return 1./cos(x);};
inline DB csc(DB x){return 1./sin(x);};

//}
// <<= '1. Bitwise Operation ., //{
namespace BO{

    inline bool _1(int x, int i){return bool(x&1<<i);}
    inline bool _1(LL x, int i){return bool(x&1LL<<i);}
    inline LL _1(int i){return 1LL<<i;}
    inline LL _U(int i){return _1(i) - 1;};

    inline int reverse_bits(int x){
        x = ((x >> 1) & 0x55555555) | ((x << 1) & 0xaaaaaaaa);
        x = ((x >> 2) & 0x33333333) | ((x << 2) & 0xcccccccc);
        x = ((x >> 4) & 0x0f0f0f0f) | ((x << 4) & 0xf0f0f0f0);
        x = ((x >> 8) & 0x00ff00ff) | ((x << 8) & 0xff00ff00);
        x = ((x >>16) & 0x0000ffff) | ((x <<16) & 0xffff0000);
        return x;
    }

    inline LL reverse_bits(LL x){
        x = ((x >> 1) & 0x5555555555555555LL) | ((x << 1) & 0xaaaaaaaaaaaaaaaaLL);
        x = ((x >> 2) & 0x3333333333333333LL) | ((x << 2) & 0xccccccccccccccccLL);
        x = ((x >> 4) & 0x0f0f0f0f0f0f0f0fLL) | ((x << 4) & 0xf0f0f0f0f0f0f0f0LL);
        x = ((x >> 8) & 0x00ff00ff00ff00ffLL) | ((x << 8) & 0xff00ff00ff00ff00LL);
        x = ((x >>16) & 0x0000ffff0000ffffLL) | ((x <<16) & 0xffff0000ffff0000LL);
        x = ((x >>32) & 0x00000000ffffffffLL) | ((x <<32) & 0xffffffff00000000LL);
        return x;
    }

    template<class T> inline bool odd(T x){return x&1;}
    template<class T> inline bool even(T x){return !odd(x);}
    template<class T> inline T low_bit(T x) {return x & -x;}
    template<class T> inline T high_bit(T x) {T p = low_bit(x);while (p != x) x -= p, p = low_bit(x);return p;}
    template<class T> inline T cover_bit(T x){T p = 1; while (p < x) p <<= 1;return p;}
    template<class T> inline int cover_idx(T x){int p = 0; while (_1(p) < x ) ++p; return p;}

    inline int clz(int x){return __builtin_clz(x);}
    inline int clz(LL x){return __builtin_clzll(x);}
    inline int ctz(int x){return __builtin_ctz(x);}
    inline int ctz(LL x){return __builtin_ctzll(x);}
    inline int lg2(int x){return !x ? -1 : 31 - clz(x);}
    inline int lg2(LL x){return !x ? -1 : 63 - clz(x);}
    inline int low_idx(int x){return !x ? -1 : ctz(x);}
    inline int low_idx(LL x){return !x ? -1 : ctz(x);}
    inline int high_idx(int x){return lg2(x);}
    inline int high_idx(LL x){return lg2(x);}
    inline int parity(int x){return __builtin_parity(x);}
    inline int parity(LL x){return __builtin_parityll(x);}
    inline int count_bits(int x){return __builtin_popcount(x);}
    inline int count_bits(LL x){return __builtin_popcountll(x);}

} using namespace BO;//}

// <<= '2. Number Theory .,//{
namespace NT{
#define gcd __gcd
    inline LL lcm(LL a, LL b){return a*b/gcd(a,b);}

    inline void INC(int &a, int b){a += b; if (a >= MOD) a -= MOD;}
    inline int sum(int a, int b){a += b; if (a >= MOD) a -= MOD; return a;}

    /* 模数两倍刚好超 int 时。
     inline int sum(uint a, int b){a += b; a %= MOD;if (a < 0) a += MOD; return a;}
     inline void INC(int &a, int b){a = sum(a, b);}
     */

    inline void DEC(int &a, int b){a -= b; if (a < 0) a += MOD;}
    inline int dff(int a, int b){a -= b; if (a < 0) a  += MOD; return a;}
    inline void MUL(int &a, int b){a = (LL)a * b % MOD;}
    //inline int pdt(int a, int b){return (LL)a * b % MOD;}
    inline int pdt(int x,int y) {
        int ret; __asm__ __volatile__ ("\tmull %ebx\n\tdivl %ecx\n":"=d"(ret):"a"(x),"b"(y),"c"(MOD));
        return ret;
    }

    inline int gcd(int m, int n, int &x, int &y){

        x = 1, y = 0; int xx = 0, yy = 1, q;

        while (1){
            q = m / n, m %= n;
            if (!m){x = xx, y = yy; return n;}
            DEC(x, pdt(q, xx)), DEC(y, pdt(q, yy));
            q = n / m, n %= m;
            if (!n) return m;
            DEC(xx, pdt(q, x)), DEC(yy, pdt(q, y));
        }
    }

    inline int sum(int a, int b, int c){return sum(a, sum(b, c));}
    inline int sum(int a, int b, int c, int d){return sum(sum(a, b), sum(c, d));}
    inline int pdt(int a, int b, int c){return pdt(a, pdt(b, c));}
    inline int pdt(int a, int b, int c, int d){return pdt(pdt(a, b), pdt(c, d));}

    inline int pow(int a, LL b){
        int c(1); while (b){
            if (b&1) MUL(c, a);
            MUL(a, a), b >>= 1;
        }
        return c;
    }

    template<class T> inline T pow(T a, LL b){
        T c(1); while (b){
            if (b&1) c *= a;
            a *= a, b >>= 1;
        }
        return c;
    }

    template<class T> inline T pow(T a, int b){
        return pow(a, (LL)b);
    }

    inline int _I(int b){
        int a = MOD, x1 = 0, x2 = 1, q; while (1){
            q = a / b, a %= b;
            if (!a) return x2;
            DEC(x1, pdt(q, x2));

            q = b / a, b %= a;
            if (!b) return x1;
            DEC(x2, pdt(q, x1));
        }
    }

    inline void DIV(int &a, int b){MUL(a, _I(b));}
    inline int qtt(int a, int b){return pdt(a, _I(b));}

    struct Int{
        int val;

        operator int() const{return val;}

        Int(int _val = 0):val(_val){
            val %= MOD; if (val < 0) val += MOD;
        }
        Int(LL _val):val(_val){
            _val %= MOD; if (_val < 0) _val += MOD;
            val = _val;
        }

        Int& operator +=(const int& rhs){INC(val, rhs);rTs;}
        Int operator +(const int& rhs) const{return sum(val, rhs);}
        Int& operator -=(const int& rhs){DEC(val, rhs);rTs;}
        Int operator -(const int& rhs) const{return dff(val, rhs);}
        Int& operator *=(const int& rhs){MUL(val, rhs);rTs;}
        Int operator *(const int& rhs) const{return pdt(val, rhs);}
        Int& operator /=(const int& rhs){DIV(val, rhs);rTs;}
        Int operator /(const int& rhs) const{return qtt(val, rhs);}
        Int operator-()const{return MOD-*this;}
    };

} using namespace NT;//}

//}

/** I/O Accelerator Interface .. **/ //{
#define g (c=getchar())
#define d isdigit(g)
#define p x=x*10+c-'0'
#define n x=x*10+'0'-c
#define pp l/=10,p
#define nn l/=10,n
template<class T> inline T& RD(T &x){
    char c;while(!d);x=c-'0';while(d)p;
    return x;
}
template<class T> inline T& RDD(T &x){
    char c;while(g,c!='-'&&!isdigit(c));
    if (c=='-'){x='0'-g;while(d)n;}
    else{x=c-'0';while(d)p;}
    return x;
}
inline DB& RF(DB &x){
    //scanf("%lf", &x);
    char c;while(g,c!='-'&&c!='.'&&!isdigit(c));
    if(c=='-')if(g=='.'){x=0;DB l=1;while(d)nn;x*=l;}
    else{x='0'-c;while(d)n;if(c=='.'){DB l=1;while(d)nn;x*=l;}}
    else if(c=='.'){x=0;DB l=1;while(d)pp;x*=l;}
    else{x=c-'0';while(d)p;if(c=='.'){DB l=1;while(d)pp;x*=l;}}
    return x;
}
#undef nn
#undef pp
#undef n
#undef p
#undef d
#undef g
inline char* RS(char *s){
    //gets(s);
    scanf("%s", s);
    return s;
}

LL last_ans; int Case; template<class T> inline void OT(const T &x){
    //printf("Case #%d: ", ++Case);
    //printf("%lld\n", x);
    //printf("%I64d\n", x);
    //printf("%.9f\n", x);
    //printf("%d\n", x);
    cout << x << endl;
    //last_ans = x;
}

//}/* .................................................................................................................................. */
//树状数组 题意：正数插入，负数abs()位置删除 节点删除直接置为0就可
const int MAXN = 1e6+50;
int v[MAXN], n, q;
class Bit{
public:
    int a[MAXN];
    void update(int x, int val){
        for(; x <= n; x += low_bit(x)) {
            a[x] += val;
        }
    }
    int query(int x) {
        int ans = 0;
        for(; x; x -= low_bit(x)) ans += a[x];
        return ans;
    }
} In;
int main(){
    RD(n, q);
    REP(i, n) {
        int inp; RD(inp);
        In.update(inp, 1);
        v[inp]++;
    }
    FOR_1(i, 1, q) {
        int x; cin >> x;
        if (x >= 0){
            In.update(x, 1), v[x]++;
        }
        else {
            int k = -x, l = 1, r = n;
            while(l <= r){
                int mid = (l + r) >> 1;
                int res = In.query(mid);
                if (res >= k) {
                    int lst = In.query(mid - 1);
                    if (v[mid]) {
                        if (lst < k){
                            In.update(mid, -1);
                            v[mid]--;
                            break;
                        }
                        else {
                            r = mid - 1;
                        }
                    }
                    else {
                        r = mid - 1;
                    }
                }
                else if (res < k) l = mid + 1;
            }
        }
    }
    for(int i = 1; i <= n; i++){
        if(v[i]) {
            return printf("%d\n", i) * 0;
        }
    }
    OT("0");
    return 0;

}


#include<bits/stdc++.h>
#define endl '\n'
#define null NULL
#define ls p<<1
#define rs p<<1|1
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define ll long long
//#define int long long
#define vi vector<int>
#define mii map<int,int>
#define pii pair<int,int>
#define ull unsigned long long
#define all(x) x.begin(),x.end()
#define IOS ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define ct cerr<<"Time elapsed:"<<1.0*clock()/CLOCKS_PER_SEC<<"s.\n";
char *fs,*ft,buf[1<<20];
#define gc() (fs==ft&&(ft=(fs=buf)+fread(buf,1,1<<20,stdin),fs==ft))?0:*fs++;
inline int read(){int x=0,f=1;char ch=gc();
while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=gc();}
while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=gc();}
return x*f;}
using namespace std;
const int N=1e6+5;
const int inf=0x7fffffff;
const int mod=998244353;
const double eps=1e-6;
const double PI=acos(-1);
int sum[N<<2];
void in(int p,int l,int r,int k)
{
    if(l==r)
    {
        sum[p]++;
        return ;
    }
    int mid=l+r>>1;
    if(k<=mid)
        in(ls,l,mid,k);
    else
        in(rs,mid+1,r,k);
    sum[p]=sum[ls]+sum[rs];
}
void del(int p,int l,int r,int k)
{
    if(l==r)
    {
        sum[p]--;
        return ;
    }
    int mid=l+r>>1;
    if(sum[ls]>=k)
        del(ls,l,mid,k);
    else
        del(rs,mid+1,r,k-sum[ls]);
    sum[p]=sum[ls]+sum[rs];
}
int ask(int p,int l,int r)
{
    if(l==r)
    {
        return l;
    }
    int mid=l+r>>1;
    if(sum[ls]!=0)
        return ask(ls,l,mid);
    if(sum[rs]!=0)
        return ask(rs,mid+1,r);
}
signed main()
{
    int n, q; cin >> n >> q;
    for(int i=1;i<=n;i++)
    {
        int x; cin >> x;
        in(1,1,n,x);
    }
    while(q--)
    {
        int x; cin >> x;
        if(x>0)
            in(1,1,n,x);
        else
        {
            x=-x;
            del(1,1,n,x);
        }
    }
    if(sum[1]!=0)
    {
        cout<<ask(1,1,n)<<endl;
    }
    else
        cout<<0<<endl;
}


#pragma comment(linker, "/STACK:36777216")
//#pragma GCC optimize ("O2")
/**
 *    This code has been written by YueGuang, feel free to ask me question. Blog: http://www.moonl1ght.xyz
 *    created:
 */
#define LOCAL
#include <functional>
#include <algorithm>
#include <iostream>
#include <fstream>
#include <sstream>
#include <iomanip>
#include <numeric>
#include <cstring>
#include <climits>
#include <cassert>
#include <complex>
#include <cstdio>
#include <string>
#include <vector>
#include <bitset>
#include <queue>
#include <stack>
#include <cmath>
#include <ctime>
#include <list>
#include <set>
#include <map>

//#include <tr1/unordered_set>
//#include <tr1/unordered_map>
//#include <array>

using namespace std;

#define REP(i, n) for (int i=0;i<n;++i)
#define FOR(i, a, b) for (int i=a;i<b;++i)
#define DWN(i, b, a) for (int i=b-1;i>=a;--i)
#define REP_1(i, n) for (int i=1;i<=n;++i)
#define FOR_1(i, a, b) for (int i=a;i<=b;++i)
#define DWN_1(i, b, a) for (int i=b;i>=a;--i)
#define REP_C(i, n) for (int n____=n,i=0;i<n____;++i)
#define FOR_C(i, a, b) for (int b____=b,i=a;i<b____;++i)
#define DWN_C(i, b, a) for (int a____=a,i=b-1;i>=a____;--i)
#define REP_N(i, n) for (i=0;i<n;++i)
#define FOR_N(i, a, b) for (i=a;i<b;++i)
#define DWN_N(i, b, a) for (i=b-1;i>=a;--i)
#define REP_1_C(i, n) for (int n____=n,i=1;i<=n____;++i)
#define FOR_1_C(i, a, b) for (int b____=b,i=a;i<=b____;++i)
#define DWN_1_C(i, b, a) for (int a____=a,i=b;i>=a____;--i)
#define REP_1_N(i, n) for (i=1;i<=n;++i)
#define FOR_1_N(i, a, b) for (i=a;i<=b;++i)
#define DWN_1_N(i, b, a) for (i=b;i>=a;--i)
#define REP_C_N(i, n) for (int n____=(i=0,n);i<n____;++i)
#define FOR_C_N(i, a, b) for (int b____=(i=0,b);i<b____;++i)
#define DWN_C_N(i, b, a) for (int a____=(i=b-1,a);i>=a____;--i)
#define REP_1_C_N(i, n) for (int n____=(i=1,n);i<=n____;++i)
#define FOR_1_C_N(i, a, b) for (int b____=(i=a,b);i<=b____;++i)
#define DWN_1_C_N(i, b, a) for (int a____=(i=b,a);i>=a____;--i)

#define ECH(it, A) for (__typeof((A).begin()) it=(A).begin(); it != (A).end(); ++it)
#define rECH(it, A) for (__typeof((A).rbegin()) it=(A).rbegin(); it != (A).rend(); ++it)
#define REP_S(i, str) for (char*i=str;*i;++i)
#define REP_L(i, hd, suc) for (int i=hd;i;i=suc[i])
#define REP_G(i, u) REP_L(i,hd[u],suc)
#define REP_SS(x, s) for (int x=s;x;x=(x-1)&s)
#define DO(n) for ( int ____n = n; ____n-->0; )
#define REP_2(i, j, n, m) REP(i, n) REP(j, m)
#define REP_2_1(i, j, n, m) REP_1(i, n) REP_1(j, m)
#define REP_3(i, j, k, n, m, l) REP(i, n) REP(j, m) REP(k, l)
#define REP_3_1(i, j, k, n, m, l) REP_1(i, n) REP_1(j, m) REP_1(k, l)
#define REP_4(i, j, k, ii, n, m, l, nn) REP(i, n) REP(j, m) REP(k, l) REP(ii, nn)
#define REP_4_1(i, j, k, ii, n, m, l, nn) REP_1(i, n) REP_1(j, m) REP_1(k, l) REP_1(ii, nn)

#define ALL(A) A.begin(), A.end()
#define LLA(A) A.rbegin(), A.rend()
#define CPY(A, B) memcpy(A, B, sizeof(A))
#define INS(A, P, B) A.insert(A.begin() + P, B)
#define ERS(A, P) A.erase(A.begin() + P)
#define LBD(A, x) (lower_bound(ALL(A), x) - A.begin())
#define UBD(A, x) (upper_bound(ALL(A), x) - A.begin())
#define CTN(T, x) (T.find(x) != T.end())
#define SZ(A) int((A).size())
#define PB push_back
#define MP(A, B) make_pair(A, B)
#define PTT pair<T, T>
#define Ts *this
#define rTs return Ts
#define fi first
#define se second
#define re real()
#define im imag()

#define Rush for(int ____T=RD(); ____T--;)
#define Display(A, n, m) {                      \
REP(i, n){                                    \
REP(j, m-1) cout << A[i][j] << " ";     \
cout << A[i][m-1] << endl;                \
}                                            \
}
#define Display_1(A, n, m) {                    \
REP_1(i, n){                                \
REP_1(j, m-1) cout << A[i][j] << " ";   \
cout << A[i][m] << endl;                \
}                                            \
}

typedef long long LL;
//typedef long double DB;
typedef double DB;
typedef unsigned uint;
typedef unsigned long long uLL;

typedef vector<int> VI;
typedef vector<char> VC;
typedef vector<string> VS;
typedef vector<LL> VL;
typedef vector<DB> VF;
typedef set<int> SI;
typedef set<string> SS;
typedef map<int, int> MII;
typedef map<string, int> MSI;
typedef pair<int, int> PII;
typedef pair<LL, LL> PLL;
typedef vector<PII> VII;
typedef vector<VI> VVI;
typedef vector<VII> VVII;

template<class T> inline T& RD(T &);
template<class T> inline void OT(const T &);
//inline int RD(){int x; return RD(x);}
inline LL RD(){LL x; return RD(x);}
inline DB& RF(DB &);
inline DB RF(){DB x; return RF(x);}
inline char* RS(char *s);
inline char& RC(char &c);
inline char RC();
inline char& RC(char &c){scanf(" %c", &c); return c;}
inline char RC(){char c; return RC(c);}
//inline char& RC(char &c){c = getchar(); return c;}
//inline char RC(){return getchar();}

template<class T> inline T& RDD(T &);
inline LL RDD(){LL x; return RDD(x);}

template<class T0, class T1> inline T0& RD(T0 &x0, T1 &x1){RD(x0), RD(x1); return x0;}
template<class T0, class T1, class T2> inline T0& RD(T0 &x0, T1 &x1, T2 &x2){RD(x0), RD(x1), RD(x2); return x0;}
template<class T0, class T1, class T2, class T3> inline T0& RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3){RD(x0), RD(x1), RD(x2), RD(x3); return x0;}
template<class T0, class T1, class T2, class T3, class T4> inline T0& RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4){RD(x0), RD(x1), RD(x2), RD(x3), RD(x4); return x0;}
template<class T0, class T1, class T2, class T3, class T4, class T5> inline T0& RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4, T5 &x5){RD(x0), RD(x1), RD(x2), RD(x3), RD(x4), RD(x5); return x0;}
template<class T0, class T1, class T2, class T3, class T4, class T5, class T6> inline T0& RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4, T5 &x5, T6 &x6){RD(x0), RD(x1), RD(x2), RD(x3), RD(x4), RD(x5), RD(x6); return x0;}
template<class T0, class T1> inline void OT(const T0 &x0, const T1 &x1){OT(x0), OT(x1);}
template<class T0, class T1, class T2> inline void OT(const T0 &x0, const T1 &x1, const T2 &x2){OT(x0), OT(x1), OT(x2);}
template<class T0, class T1, class T2, class T3> inline void OT(const T0 &x0, const T1 &x1, const T2 &x2, const T3 &x3){OT(x0), OT(x1), OT(x2), OT(x3);}
template<class T0, class T1, class T2, class T3, class T4> inline void OT(const T0 &x0, const T1 &x1, const T2 &x2, const T3 &x3, const T4 &x4){OT(x0), OT(x1), OT(x2), OT(x3), OT(x4);}
template<class T0, class T1, class T2, class T3, class T4, class T5> inline void OT(const T0 &x0, const T1 &x1, const T2 &x2, const T3 &x3, const T4 &x4, const T5 &x5){OT(x0), OT(x1), OT(x2), OT(x3), OT(x4), OT(x5);}
template<class T0, class T1, class T2, class T3, class T4, class T5, class T6> inline void OT(const T0 &x0, const T1 &x1, const T2 &x2, const T3 &x3, const T4 &x4, const T5 &x5, const T6 &x6){OT(x0), OT(x1), OT(x2), OT(x3), OT(x4), OT(x5), OT(x6);}
inline char& RC(char &a, char &b){RC(a), RC(b); return a;}
inline char& RC(char &a, char &b, char &c){RC(a), RC(b), RC(c); return a;}
inline char& RC(char &a, char &b, char &c, char &d){RC(a), RC(b), RC(c), RC(d); return a;}
inline char& RC(char &a, char &b, char &c, char &d, char &e){RC(a), RC(b), RC(c), RC(d), RC(e); return a;}
inline char& RC(char &a, char &b, char &c, char &d, char &e, char &f){RC(a), RC(b), RC(c), RC(d), RC(e), RC(f); return a;}
inline char& RC(char &a, char &b, char &c, char &d, char &e, char &f, char &g){RC(a), RC(b), RC(c), RC(d), RC(e), RC(f), RC(g); return a;}
inline DB& RF(DB &a, DB &b){RF(a), RF(b); return a;}
inline DB& RF(DB &a, DB &b, DB &c){RF(a), RF(b), RF(c); return a;}
inline DB& RF(DB &a, DB &b, DB &c, DB &d){RF(a), RF(b), RF(c), RF(d); return a;}
inline DB& RF(DB &a, DB &b, DB &c, DB &d, DB &e){RF(a), RF(b), RF(c), RF(d), RF(e); return a;}
inline DB& RF(DB &a, DB &b, DB &c, DB &d, DB &e, DB &f){RF(a), RF(b), RF(c), RF(d), RF(e), RF(f); return a;}
inline DB& RF(DB &a, DB &b, DB &c, DB &d, DB &e, DB &f, DB &g){RF(a), RF(b), RF(c), RF(d), RF(e), RF(f), RF(g); return a;}
inline void RS(char *s1, char *s2){RS(s1), RS(s2);}
inline void RS(char *s1, char *s2, char *s3){RS(s1), RS(s2), RS(s3);}
template<class T0,class T1>inline T0& RDD(T0&a, T1&b){RDD(a),RDD(b); return a;}
template<class T0,class T1,class T2>inline T1& RDD(T0&a, T1&b, T2&c){RDD(a),RDD(b),RDD(c); return a;}

template<class T> inline void RST(T &A){memset(A, 0, sizeof(A));}
template<class T> inline void FLC(T &A, int x){memset(A, x, sizeof(A));}
template<class T> inline void CLR(T &A){A.clear();}

template<class T0, class T1> inline void RST(T0 &A0, T1 &A1){RST(A0), RST(A1);}
template<class T0, class T1, class T2> inline void RST(T0 &A0, T1 &A1, T2 &A2){RST(A0), RST(A1), RST(A2);}
template<class T0, class T1, class T2, class T3> inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3){RST(A0), RST(A1), RST(A2), RST(A3);}
template<class T0, class T1, class T2, class T3, class T4> inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4){RST(A0), RST(A1), RST(A2), RST(A3), RST(A4);}
template<class T0, class T1, class T2, class T3, class T4, class T5> inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5){RST(A0), RST(A1), RST(A2), RST(A3), RST(A4), RST(A5);}
template<class T0, class T1, class T2, class T3, class T4, class T5, class T6> inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5, T6 &A6){RST(A0), RST(A1), RST(A2), RST(A3), RST(A4), RST(A5), RST(A6);}
template<class T0, class T1> inline void FLC(T0 &A0, T1 &A1, int x){FLC(A0, x), FLC(A1, x);}
template<class T0, class T1, class T2> inline void FLC(T0 &A0, T1 &A1, T2 &A2, int x){FLC(A0, x), FLC(A1, x), FLC(A2, x);}
template<class T0, class T1, class T2, class T3> inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3, int x){FLC(A0, x), FLC(A1, x), FLC(A2, x), FLC(A3, x);}
template<class T0, class T1, class T2, class T3, class T4> inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, int x){FLC(A0, x), FLC(A1, x), FLC(A2, x), FLC(A3, x), FLC(A4, x);}
template<class T0, class T1, class T2, class T3, class T4, class T5> inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5, int x){FLC(A0, x), FLC(A1, x), FLC(A2, x), FLC(A3, x), FLC(A4, x), FLC(A5, x);}
template<class T0, class T1, class T2, class T3, class T4, class T5, class T6> inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5, T6 &A6, int x){FLC(A0, x), FLC(A1, x), FLC(A2, x), FLC(A3, x), FLC(A4, x), FLC(A5, x), FLC(A6, x);}
template<class T> inline void CLR(priority_queue<T, vector<T>, less<T> > &Q){while (!Q.empty()) Q.pop();}
template<class T> inline void CLR(priority_queue<T, vector<T>, greater<T> > &Q){while (!Q.empty()) Q.pop();}
template<class T> inline void CLR(stack<T> &S){while (!S.empty()) S.pop();}
template<class T> inline void CLR(queue<T> &Q){while (!Q.empty()) Q.pop();}

template<class T0, class T1> inline void CLR(T0 &A0, T1 &A1){CLR(A0), CLR(A1);}
template<class T0, class T1, class T2> inline void CLR(T0 &A0, T1 &A1, T2 &A2){CLR(A0), CLR(A1), CLR(A2);}
template<class T0, class T1, class T2, class T3> inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3){CLR(A0), CLR(A1), CLR(A2), CLR(A3);}
template<class T0, class T1, class T2, class T3, class T4> inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4){CLR(A0), CLR(A1), CLR(A2), CLR(A3), CLR(A4);}
template<class T0, class T1, class T2, class T3, class T4, class T5> inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5){CLR(A0), CLR(A1), CLR(A2), CLR(A3), CLR(A4), CLR(A5);}
template<class T0, class T1, class T2, class T3, class T4, class T5, class T6> inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5, T6 &A6){CLR(A0), CLR(A1), CLR(A2), CLR(A3), CLR(A4), CLR(A5), CLR(A6);}
template<class T> inline void CLR(T &A, int n){REP(i, n) CLR(A[i]);}

template<class T> inline bool EPT(T &a){return a.empty();}
template<class T> inline T& SRT(T &A){sort(ALL(A)); return A;}
template<class T, class C> inline T& SRT(T &A, C cmp){sort(ALL(A), cmp); return A;}
template<class T> inline T& RVS(T &A){reverse(ALL(A)); return A;}
template<class T> inline T& UNQQ(T &A){A.resize(unique(ALL(A))-A.begin());return A;}
template<class T> inline T& UNQ(T &A){SRT(A);return UNQQ(A);}
template<class T, class C> inline T& UNQ(T &A, C cmp){SRT(A, cmp);return UNQQ(A);}

//}

/** Constant List .. **/ //{

const int MOD = int(1e9) + 7;
const int INF = 0x3f3f3f3f;
const LL INFF = 0x3f3f3f3f3f3f3f3fLL;
const DB EPS = 1e-9;
const DB OO = 1e20;
const DB PI = acos(-1.0); //M_PI;

const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, 1, 0, -1};

//}

/** Add On .. **/ //{
// <<= '0. Nichi Joo ., //{

template<class T> inline bool checkMin(T &a,const T b){return b < a ? a = b, 1 : 0;}
template<class T> inline bool checkMax(T &a,const T b){return a < b ? a = b, 1 : 0;}
template <class T, class C> inline bool checkUpd(T& a, const T b, C c){return c(b,a) ? a = b, 1 : 0;}
template<class T> inline T min(T a, T b, T c){return min(min(a, b), c);}
template<class T> inline T max(T a, T b, T c){return max(max(a, b), c);}
template<class T> inline T min(T a, T b, T c, T d){return min(min(a, b), min(c, d));}
template<class T> inline T max(T a, T b, T c, T d){return max(max(a, b), max(c, d));}
template<class T> inline T min(T a, T b, T c, T d, T e){return min(min(min(a,b),min(c,d)),e);}
template<class T> inline T max(T a, T b, T c, T d, T e){return max(max(max(a,b),max(c,d)),e);}
template<class T> inline T sqr(T a){return a*a;}
template<class T> inline T cub(T a){return a*a*a;}
template<class T> inline T ceil(T x, T y){return (x - 1) / y + 1;}
template<class T> T abs(T x){return x>0?x:-x;}
inline int sgn(DB x){return x < -EPS ? -1 : x > EPS;}
inline int sgn(DB x, DB y){return sgn(x - y);}

inline DB cos(DB a, DB b, DB c){return (sqr(a)+sqr(b)-sqr(c))/(2*a*b);}
inline DB cot(DB x){return 1./tan(x);};
inline DB sec(DB x){return 1./cos(x);};
inline DB csc(DB x){return 1./sin(x);};

//}
// <<= '1. Bitwise Operation ., //{
namespace BO{

    inline bool _1(int x, int i){return bool(x&1<<i);}
    inline bool _1(LL x, int i){return bool(x&1LL<<i);}
    inline LL _1(int i){return 1LL<<i;}
    inline LL _U(int i){return _1(i) - 1;};

    inline int reverse_bits(int x){
        x = ((x >> 1) & 0x55555555) | ((x << 1) & 0xaaaaaaaa);
        x = ((x >> 2) & 0x33333333) | ((x << 2) & 0xcccccccc);
        x = ((x >> 4) & 0x0f0f0f0f) | ((x << 4) & 0xf0f0f0f0);
        x = ((x >> 8) & 0x00ff00ff) | ((x << 8) & 0xff00ff00);
        x = ((x >>16) & 0x0000ffff) | ((x <<16) & 0xffff0000);
        return x;
    }

    inline LL reverse_bits(LL x){
        x = ((x >> 1) & 0x5555555555555555LL) | ((x << 1) & 0xaaaaaaaaaaaaaaaaLL);
        x = ((x >> 2) & 0x3333333333333333LL) | ((x << 2) & 0xccccccccccccccccLL);
        x = ((x >> 4) & 0x0f0f0f0f0f0f0f0fLL) | ((x << 4) & 0xf0f0f0f0f0f0f0f0LL);
        x = ((x >> 8) & 0x00ff00ff00ff00ffLL) | ((x << 8) & 0xff00ff00ff00ff00LL);
        x = ((x >>16) & 0x0000ffff0000ffffLL) | ((x <<16) & 0xffff0000ffff0000LL);
        x = ((x >>32) & 0x00000000ffffffffLL) | ((x <<32) & 0xffffffff00000000LL);
        return x;
    }

    template<class T> inline bool odd(T x){return x&1;}
    template<class T> inline bool even(T x){return !odd(x);}
    template<class T> inline T low_bit(T x) {return x & -x;}
    template<class T> inline T high_bit(T x) {T p = low_bit(x);while (p != x) x -= p, p = low_bit(x);return p;}
    template<class T> inline T cover_bit(T x){T p = 1; while (p < x) p <<= 1;return p;}
    template<class T> inline int cover_idx(T x){int p = 0; while (_1(p) < x ) ++p; return p;}

    inline int clz(int x){return __builtin_clz(x);}
    inline int clz(LL x){return __builtin_clzll(x);}
    inline int ctz(int x){return __builtin_ctz(x);}
    inline int ctz(LL x){return __builtin_ctzll(x);}
    inline int lg2(int x){return !x ? -1 : 31 - clz(x);}
    inline int lg2(LL x){return !x ? -1 : 63 - clz(x);}
    inline int low_idx(int x){return !x ? -1 : ctz(x);}
    inline int low_idx(LL x){return !x ? -1 : ctz(x);}
    inline int high_idx(int x){return lg2(x);}
    inline int high_idx(LL x){return lg2(x);}
    inline int parity(int x){return __builtin_parity(x);}
    inline int parity(LL x){return __builtin_parityll(x);}
    inline int count_bits(int x){return __builtin_popcount(x);}
    inline int count_bits(LL x){return __builtin_popcountll(x);}

} using namespace BO;//}

// <<= '2. Number Theory .,//{
namespace NT{
#define gcd __gcd
    inline LL lcm(LL a, LL b){return a*b/gcd(a,b);}

    inline void INC(int &a, int b){a += b; if (a >= MOD) a -= MOD;}
    inline int sum(int a, int b){a += b; if (a >= MOD) a -= MOD; return a;}

    /* 模数两倍刚好超 int 时。
     inline int sum(uint a, int b){a += b; a %= MOD;if (a < 0) a += MOD; return a;}
     inline void INC(int &a, int b){a = sum(a, b);}
     */

    inline void DEC(int &a, int b){a -= b; if (a < 0) a += MOD;}
    inline int dff(int a, int b){a -= b; if (a < 0) a  += MOD; return a;}
    inline void MUL(int &a, int b){a = (LL)a * b % MOD;}
    //inline int pdt(int a, int b){return (LL)a * b % MOD;}
    inline int pdt(int x,int y) {
        int ret; __asm__ __volatile__ ("\tmull %ebx\n\tdivl %ecx\n":"=d"(ret):"a"(x),"b"(y),"c"(MOD));
        return ret;
    }

    inline int gcd(int m, int n, int &x, int &y){

        x = 1, y = 0; int xx = 0, yy = 1, q;

        while (1){
            q = m / n, m %= n;
            if (!m){x = xx, y = yy; return n;}
            DEC(x, pdt(q, xx)), DEC(y, pdt(q, yy));
            q = n / m, n %= m;
            if (!n) return m;
            DEC(xx, pdt(q, x)), DEC(yy, pdt(q, y));
        }
    }

    inline int sum(int a, int b, int c){return sum(a, sum(b, c));}
    inline int sum(int a, int b, int c, int d){return sum(sum(a, b), sum(c, d));}
    inline int pdt(int a, int b, int c){return pdt(a, pdt(b, c));}
    inline int pdt(int a, int b, int c, int d){return pdt(pdt(a, b), pdt(c, d));}

    inline int pow(int a, LL b){
        int c(1); while (b){
            if (b&1) MUL(c, a);
            MUL(a, a), b >>= 1;
        }
        return c;
    }

    template<class T> inline T pow(T a, LL b){
        T c(1); while (b){
            if (b&1) c *= a;
            a *= a, b >>= 1;
        }
        return c;
    }

    template<class T> inline T pow(T a, int b){
        return pow(a, (LL)b);
    }

    inline int _I(int b){
        int a = MOD, x1 = 0, x2 = 1, q; while (1){
            q = a / b, a %= b;
            if (!a) return x2;
            DEC(x1, pdt(q, x2));

            q = b / a, b %= a;
            if (!b) return x1;
            DEC(x2, pdt(q, x1));
        }
    }

    inline void DIV(int &a, int b){MUL(a, _I(b));}
    inline int qtt(int a, int b){return pdt(a, _I(b));}

    struct Int{
        int val;

        operator int() const{return val;}

        Int(int _val = 0):val(_val){
            val %= MOD; if (val < 0) val += MOD;
        }
        Int(LL _val):val(_val){
            _val %= MOD; if (_val < 0) _val += MOD;
            val = _val;
        }

        Int& operator +=(const int& rhs){INC(val, rhs);rTs;}
        Int operator +(const int& rhs) const{return sum(val, rhs);}
        Int& operator -=(const int& rhs){DEC(val, rhs);rTs;}
        Int operator -(const int& rhs) const{return dff(val, rhs);}
        Int& operator *=(const int& rhs){MUL(val, rhs);rTs;}
        Int operator *(const int& rhs) const{return pdt(val, rhs);}
        Int& operator /=(const int& rhs){DIV(val, rhs);rTs;}
        Int operator /(const int& rhs) const{return qtt(val, rhs);}
        Int operator-()const{return MOD-*this;}
    };

} using namespace NT;//}

//}

/** I/O Accelerator Interface .. **/ //{
#define g (c=getchar())
#define d isdigit(g)
#define p x=x*10+c-'0'
#define n x=x*10+'0'-c
#define pp l/=10,p
#define nn l/=10,n
template<class T> inline T& RD(T &x){
    char c;while(!d);x=c-'0';while(d)p;
    return x;
}
template<class T> inline T& RDD(T &x){
    char c;while(g,c!='-'&&!isdigit(c));
    if (c=='-'){x='0'-g;while(d)n;}
    else{x=c-'0';while(d)p;}
    return x;
}
inline DB& RF(DB &x){
    //scanf("%lf", &x);
    char c;while(g,c!='-'&&c!='.'&&!isdigit(c));
    if(c=='-')if(g=='.'){x=0;DB l=1;while(d)nn;x*=l;}
    else{x='0'-c;while(d)n;if(c=='.'){DB l=1;while(d)nn;x*=l;}}
    else if(c=='.'){x=0;DB l=1;while(d)pp;x*=l;}
    else{x=c-'0';while(d)p;if(c=='.'){DB l=1;while(d)pp;x*=l;}}
    return x;
}
#undef nn
#undef pp
#undef n
#undef p
#undef d
#undef g
inline char* RS(char *s){
    //gets(s);
    scanf("%s", s);
    return s;
}

LL last_ans; int Case; template<class T> inline void OT(const T &x){
    //printf("Case #%d: ", ++Case);
    //printf("%lld\n", x);
    //printf("%I64d\n", x);
    //printf("%.9f\n", x);
    //printf("%d\n", x);
    cout << x << endl;
    //last_ans = x;
}

//}/* .................................................................................................................................. */
//线段树 题意：正数插入，负数abs()位置删除 节点删除直接置为0就可
const int maxn = 1e6 + 5;
int sumt[maxn<<2];
#define lson p<<1
#define rson p<<1|1

void ins(int p,int l,int r,int k)
{
    if(l == r)
    {
        sumt[p]++;
        return ;
    }
    int mid = l + r >> 1;
    if(k <= mid)
        ins(lson, l, mid, k);
    else
        ins(rson,mid + 1, r, k);
    sumt[p] = sumt[lson] + sumt[rson];
}

void del(int p, int l, int r, int k){
    if (l == r) {sumt[p]--; return ;}
    int mid = l + r >> 1;
    if (sumt[lson] >= k) del(lson, l, mid, k);
    else del(rson, mid + 1, r, k - sumt[lson]);
    sumt[p] = sumt[lson] + sumt[rson];
}

int query(int p, int l, int r){
    if (l == r){
        return l;
    }
    int mid = l + r >> 1;
    if (sumt[lson] != 0) return query(lson, l, mid);
    if (sumt[rson] != 0) return query(rson, mid + 1, r);
}

int main(){
    int n, q; RD(n, q);
    for(int i = 1; i <= n; i++){
        int x; cin >> x; ins(1, 1, n, x);
    }
    for(int que = 1; que <= q; que++){
        int x; cin >> x;
        if (x > 0) ins(1, 1, n, x);
        else { del(1, 1, n, abs(x));}
    }
    if (sumt[1]!=0) cout << query(1, 1, n) << '\n';
    else cout << 0 << '\n';
}


#pragma comment(linker, "/STACK:36777216")
//#pragma GCC optimize ("O2")
/**
 *    This code has been written by YueGuang, feel free to ask me question. Blog: http://www.moonl1ght.xyz
 *    created:
 */
#define LOCAL
#include <functional>
#include <algorithm>
#include <iostream>
#include <fstream>
#include <sstream>
#include <iomanip>
#include <numeric>
#include <cstring>
#include <climits>
#include <cassert>
#include <complex>
#include <cstdio>
#include <string>
#include <vector>
#include <bitset>
#include <queue>
#include <stack>
#include <cmath>
#include <ctime>
#include <list>
#include <set>
#include <map>

//#include <tr1/unordered_set>
//#include <tr1/unordered_map>
//#include <array>

using namespace std;

#define REP(i, n) for (int i=0;i<n;++i)
#define FOR(i, a, b) for (int i=a;i<b;++i)
#define DWN(i, b, a) for (int i=b-1;i>=a;--i)
#define REP_1(i, n) for (int i=1;i<=n;++i)
#define FOR_1(i, a, b) for (int i=a;i<=b;++i)
#define DWN_1(i, b, a) for (int i=b;i>=a;--i)
#define REP_C(i, n) for (int n____=n,i=0;i<n____;++i)
#define FOR_C(i, a, b) for (int b____=b,i=a;i<b____;++i)
#define DWN_C(i, b, a) for (int a____=a,i=b-1;i>=a____;--i)
#define REP_N(i, n) for (i=0;i<n;++i)
#define FOR_N(i, a, b) for (i=a;i<b;++i)
#define DWN_N(i, b, a) for (i=b-1;i>=a;--i)
#define REP_1_C(i, n) for (int n____=n,i=1;i<=n____;++i)
#define FOR_1_C(i, a, b) for (int b____=b,i=a;i<=b____;++i)
#define DWN_1_C(i, b, a) for (int a____=a,i=b;i>=a____;--i)
#define REP_1_N(i, n) for (i=1;i<=n;++i)
#define FOR_1_N(i, a, b) for (i=a;i<=b;++i)
#define DWN_1_N(i, b, a) for (i=b;i>=a;--i)
#define REP_C_N(i, n) for (int n____=(i=0,n);i<n____;++i)
#define FOR_C_N(i, a, b) for (int b____=(i=0,b);i<b____;++i)
#define DWN_C_N(i, b, a) for (int a____=(i=b-1,a);i>=a____;--i)
#define REP_1_C_N(i, n) for (int n____=(i=1,n);i<=n____;++i)
#define FOR_1_C_N(i, a, b) for (int b____=(i=a,b);i<=b____;++i)
#define DWN_1_C_N(i, b, a) for (int a____=(i=b,a);i>=a____;--i)

#define ECH(it, A) for (__typeof((A).begin()) it=(A).begin(); it != (A).end(); ++it)
#define rECH(it, A) for (__typeof((A).rbegin()) it=(A).rbegin(); it != (A).rend(); ++it)
#define REP_S(i, str) for (char*i=str;*i;++i)
#define REP_L(i, hd, suc) for (int i=hd;i;i=suc[i])
#define REP_G(i, u) REP_L(i,hd[u],suc)
#define REP_SS(x, s) for (int x=s;x;x=(x-1)&s)
#define DO(n) for ( int ____n = n; ____n-->0; )
#define REP_2(i, j, n, m) REP(i, n) REP(j, m)
#define REP_2_1(i, j, n, m) REP_1(i, n) REP_1(j, m)
#define REP_3(i, j, k, n, m, l) REP(i, n) REP(j, m) REP(k, l)
#define REP_3_1(i, j, k, n, m, l) REP_1(i, n) REP_1(j, m) REP_1(k, l)
#define REP_4(i, j, k, ii, n, m, l, nn) REP(i, n) REP(j, m) REP(k, l) REP(ii, nn)
#define REP_4_1(i, j, k, ii, n, m, l, nn) REP_1(i, n) REP_1(j, m) REP_1(k, l) REP_1(ii, nn)

#define ALL(A) A.begin(), A.end()
#define LLA(A) A.rbegin(), A.rend()
#define CPY(A, B) memcpy(A, B, sizeof(A))
#define INS(A, P, B) A.insert(A.begin() + P, B)
#define ERS(A, P) A.erase(A.begin() + P)
#define LBD(A, x) (lower_bound(ALL(A), x) - A.begin())
#define UBD(A, x) (upper_bound(ALL(A), x) - A.begin())
#define CTN(T, x) (T.find(x) != T.end())
#define SZ(A) int((A).size())
#define PB push_back
#define MP(A, B) make_pair(A, B)
#define PTT pair<T, T>
#define Ts *this
#define rTs return Ts
#define fi first
#define se second
#define re real()
#define im imag()

#define Rush for(int ____T=RD(); ____T--;)
#define Display(A, n, m) {                      \
REP(i, n){                                    \
REP(j, m-1) cout << A[i][j] << " ";     \
cout << A[i][m-1] << endl;                \
}                                            \
}
#define Display_1(A, n, m) {                    \
REP_1(i, n){                                \
REP_1(j, m-1) cout << A[i][j] << " ";   \
cout << A[i][m] << endl;                \
}                                            \
}

typedef long long LL;
//typedef long double DB;
typedef double DB;
typedef unsigned uint;
typedef unsigned long long uLL;

typedef vector<int> VI;
typedef vector<char> VC;
typedef vector<string> VS;
typedef vector<LL> VL;
typedef vector<DB> VF;
typedef set<int> SI;
typedef set<string> SS;
typedef map<int, int> MII;
typedef map<string, int> MSI;
typedef pair<int, int> PII;
typedef pair<LL, LL> PLL;
typedef vector<PII> VII;
typedef vector<VI> VVI;
typedef vector<VII> VVII;

template<class T> inline T& RD(T &);
template<class T> inline void OT(const T &);
//inline int RD(){int x; return RD(x);}
inline LL RD(){LL x; return RD(x);}
inline DB& RF(DB &);
inline DB RF(){DB x; return RF(x);}
inline char* RS(char *s);
inline char& RC(char &c);
inline char RC();
inline char& RC(char &c){scanf(" %c", &c); return c;}
inline char RC(){char c; return RC(c);}
//inline char& RC(char &c){c = getchar(); return c;}
//inline char RC(){return getchar();}

template<class T> inline T& RDD(T &);
inline LL RDD(){LL x; return RDD(x);}

template<class T0, class T1> inline T0& RD(T0 &x0, T1 &x1){RD(x0), RD(x1); return x0;}
template<class T0, class T1, class T2> inline T0& RD(T0 &x0, T1 &x1, T2 &x2){RD(x0), RD(x1), RD(x2); return x0;}
template<class T0, class T1, class T2, class T3> inline T0& RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3){RD(x0), RD(x1), RD(x2), RD(x3); return x0;}
template<class T0, class T1, class T2, class T3, class T4> inline T0& RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4){RD(x0), RD(x1), RD(x2), RD(x3), RD(x4); return x0;}
template<class T0, class T1, class T2, class T3, class T4, class T5> inline T0& RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4, T5 &x5){RD(x0), RD(x1), RD(x2), RD(x3), RD(x4), RD(x5); return x0;}
template<class T0, class T1, class T2, class T3, class T4, class T5, class T6> inline T0& RD(T0 &x0, T1 &x1, T2 &x2, T3 &x3, T4 &x4, T5 &x5, T6 &x6){RD(x0), RD(x1), RD(x2), RD(x3), RD(x4), RD(x5), RD(x6); return x0;}
template<class T0, class T1> inline void OT(const T0 &x0, const T1 &x1){OT(x0), OT(x1);}
template<class T0, class T1, class T2> inline void OT(const T0 &x0, const T1 &x1, const T2 &x2){OT(x0), OT(x1), OT(x2);}
template<class T0, class T1, class T2, class T3> inline void OT(const T0 &x0, const T1 &x1, const T2 &x2, const T3 &x3){OT(x0), OT(x1), OT(x2), OT(x3);}
template<class T0, class T1, class T2, class T3, class T4> inline void OT(const T0 &x0, const T1 &x1, const T2 &x2, const T3 &x3, const T4 &x4){OT(x0), OT(x1), OT(x2), OT(x3), OT(x4);}
template<class T0, class T1, class T2, class T3, class T4, class T5> inline void OT(const T0 &x0, const T1 &x1, const T2 &x2, const T3 &x3, const T4 &x4, const T5 &x5){OT(x0), OT(x1), OT(x2), OT(x3), OT(x4), OT(x5);}
template<class T0, class T1, class T2, class T3, class T4, class T5, class T6> inline void OT(const T0 &x0, const T1 &x1, const T2 &x2, const T3 &x3, const T4 &x4, const T5 &x5, const T6 &x6){OT(x0), OT(x1), OT(x2), OT(x3), OT(x4), OT(x5), OT(x6);}
inline char& RC(char &a, char &b){RC(a), RC(b); return a;}
inline char& RC(char &a, char &b, char &c){RC(a), RC(b), RC(c); return a;}
inline char& RC(char &a, char &b, char &c, char &d){RC(a), RC(b), RC(c), RC(d); return a;}
inline char& RC(char &a, char &b, char &c, char &d, char &e){RC(a), RC(b), RC(c), RC(d), RC(e); return a;}
inline char& RC(char &a, char &b, char &c, char &d, char &e, char &f){RC(a), RC(b), RC(c), RC(d), RC(e), RC(f); return a;}
inline char& RC(char &a, char &b, char &c, char &d, char &e, char &f, char &g){RC(a), RC(b), RC(c), RC(d), RC(e), RC(f), RC(g); return a;}
inline DB& RF(DB &a, DB &b){RF(a), RF(b); return a;}
inline DB& RF(DB &a, DB &b, DB &c){RF(a), RF(b), RF(c); return a;}
inline DB& RF(DB &a, DB &b, DB &c, DB &d){RF(a), RF(b), RF(c), RF(d); return a;}
inline DB& RF(DB &a, DB &b, DB &c, DB &d, DB &e){RF(a), RF(b), RF(c), RF(d), RF(e); return a;}
inline DB& RF(DB &a, DB &b, DB &c, DB &d, DB &e, DB &f){RF(a), RF(b), RF(c), RF(d), RF(e), RF(f); return a;}
inline DB& RF(DB &a, DB &b, DB &c, DB &d, DB &e, DB &f, DB &g){RF(a), RF(b), RF(c), RF(d), RF(e), RF(f), RF(g); return a;}
inline void RS(char *s1, char *s2){RS(s1), RS(s2);}
inline void RS(char *s1, char *s2, char *s3){RS(s1), RS(s2), RS(s3);}
template<class T0,class T1>inline T0& RDD(T0&a, T1&b){RDD(a),RDD(b); return a;}
template<class T0,class T1,class T2>inline T1& RDD(T0&a, T1&b, T2&c){RDD(a),RDD(b),RDD(c); return a;}

template<class T> inline void RST(T &A){memset(A, 0, sizeof(A));}
template<class T> inline void FLC(T &A, int x){memset(A, x, sizeof(A));}
template<class T> inline void CLR(T &A){A.clear();}

template<class T0, class T1> inline void RST(T0 &A0, T1 &A1){RST(A0), RST(A1);}
template<class T0, class T1, class T2> inline void RST(T0 &A0, T1 &A1, T2 &A2){RST(A0), RST(A1), RST(A2);}
template<class T0, class T1, class T2, class T3> inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3){RST(A0), RST(A1), RST(A2), RST(A3);}
template<class T0, class T1, class T2, class T3, class T4> inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4){RST(A0), RST(A1), RST(A2), RST(A3), RST(A4);}
template<class T0, class T1, class T2, class T3, class T4, class T5> inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5){RST(A0), RST(A1), RST(A2), RST(A3), RST(A4), RST(A5);}
template<class T0, class T1, class T2, class T3, class T4, class T5, class T6> inline void RST(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5, T6 &A6){RST(A0), RST(A1), RST(A2), RST(A3), RST(A4), RST(A5), RST(A6);}
template<class T0, class T1> inline void FLC(T0 &A0, T1 &A1, int x){FLC(A0, x), FLC(A1, x);}
template<class T0, class T1, class T2> inline void FLC(T0 &A0, T1 &A1, T2 &A2, int x){FLC(A0, x), FLC(A1, x), FLC(A2, x);}
template<class T0, class T1, class T2, class T3> inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3, int x){FLC(A0, x), FLC(A1, x), FLC(A2, x), FLC(A3, x);}
template<class T0, class T1, class T2, class T3, class T4> inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, int x){FLC(A0, x), FLC(A1, x), FLC(A2, x), FLC(A3, x), FLC(A4, x);}
template<class T0, class T1, class T2, class T3, class T4, class T5> inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5, int x){FLC(A0, x), FLC(A1, x), FLC(A2, x), FLC(A3, x), FLC(A4, x), FLC(A5, x);}
template<class T0, class T1, class T2, class T3, class T4, class T5, class T6> inline void FLC(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5, T6 &A6, int x){FLC(A0, x), FLC(A1, x), FLC(A2, x), FLC(A3, x), FLC(A4, x), FLC(A5, x), FLC(A6, x);}
template<class T> inline void CLR(priority_queue<T, vector<T>, less<T> > &Q){while (!Q.empty()) Q.pop();}
template<class T> inline void CLR(priority_queue<T, vector<T>, greater<T> > &Q){while (!Q.empty()) Q.pop();}
template<class T> inline void CLR(stack<T> &S){while (!S.empty()) S.pop();}
template<class T> inline void CLR(queue<T> &Q){while (!Q.empty()) Q.pop();}

template<class T0, class T1> inline void CLR(T0 &A0, T1 &A1){CLR(A0), CLR(A1);}
template<class T0, class T1, class T2> inline void CLR(T0 &A0, T1 &A1, T2 &A2){CLR(A0), CLR(A1), CLR(A2);}
template<class T0, class T1, class T2, class T3> inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3){CLR(A0), CLR(A1), CLR(A2), CLR(A3);}
template<class T0, class T1, class T2, class T3, class T4> inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4){CLR(A0), CLR(A1), CLR(A2), CLR(A3), CLR(A4);}
template<class T0, class T1, class T2, class T3, class T4, class T5> inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5){CLR(A0), CLR(A1), CLR(A2), CLR(A3), CLR(A4), CLR(A5);}
template<class T0, class T1, class T2, class T3, class T4, class T5, class T6> inline void CLR(T0 &A0, T1 &A1, T2 &A2, T3 &A3, T4 &A4, T5 &A5, T6 &A6){CLR(A0), CLR(A1), CLR(A2), CLR(A3), CLR(A4), CLR(A5), CLR(A6);}
template<class T> inline void CLR(T &A, int n){REP(i, n) CLR(A[i]);}

template<class T> inline bool EPT(T &a){return a.empty();}
template<class T> inline T& SRT(T &A){sort(ALL(A)); return A;}
template<class T, class C> inline T& SRT(T &A, C cmp){sort(ALL(A), cmp); return A;}
template<class T> inline T& RVS(T &A){reverse(ALL(A)); return A;}
template<class T> inline T& UNQQ(T &A){A.resize(unique(ALL(A))-A.begin());return A;}
template<class T> inline T& UNQ(T &A){SRT(A);return UNQQ(A);}
template<class T, class C> inline T& UNQ(T &A, C cmp){SRT(A, cmp);return UNQQ(A);}

//}

/** Constant List .. **/ //{

const int MOD = int(1e9) + 7;
const int INF = 0x3f3f3f3f;
const LL INFF = 0x3f3f3f3f3f3f3f3fLL;
const DB EPS = 1e-9;
const DB OO = 1e20;
const DB PI = acos(-1.0); //M_PI;

const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, 1, 0, -1};

//}

/** Add On .. **/ //{
// <<= '0. Nichi Joo ., //{

template<class T> inline bool checkMin(T &a,const T b){return b < a ? a = b, 1 : 0;}
template<class T> inline bool checkMax(T &a,const T b){return a < b ? a = b, 1 : 0;}
template <class T, class C> inline bool checkUpd(T& a, const T b, C c){return c(b,a) ? a = b, 1 : 0;}
template<class T> inline T min(T a, T b, T c){return min(min(a, b), c);}
template<class T> inline T max(T a, T b, T c){return max(max(a, b), c);}
template<class T> inline T min(T a, T b, T c, T d){return min(min(a, b), min(c, d));}
template<class T> inline T max(T a, T b, T c, T d){return max(max(a, b), max(c, d));}
template<class T> inline T min(T a, T b, T c, T d, T e){return min(min(min(a,b),min(c,d)),e);}
template<class T> inline T max(T a, T b, T c, T d, T e){return max(max(max(a,b),max(c,d)),e);}
template<class T> inline T sqr(T a){return a*a;}
template<class T> inline T cub(T a){return a*a*a;}
template<class T> inline T ceil(T x, T y){return (x - 1) / y + 1;}
template<class T> T abs(T x){return x>0?x:-x;}
inline int sgn(DB x){return x < -EPS ? -1 : x > EPS;}
inline int sgn(DB x, DB y){return sgn(x - y);}

inline DB cos(DB a, DB b, DB c){return (sqr(a)+sqr(b)-sqr(c))/(2*a*b);}
inline DB cot(DB x){return 1./tan(x);};
inline DB sec(DB x){return 1./cos(x);};
inline DB csc(DB x){return 1./sin(x);};

//}
// <<= '1. Bitwise Operation ., //{
namespace BO{

    inline bool _1(int x, int i){return bool(x&1<<i);}
    inline bool _1(LL x, int i){return bool(x&1LL<<i);}
    inline LL _1(int i){return 1LL<<i;}
    inline LL _U(int i){return _1(i) - 1;};

    inline int reverse_bits(int x){
        x = ((x >> 1) & 0x55555555) | ((x << 1) & 0xaaaaaaaa);
        x = ((x >> 2) & 0x33333333) | ((x << 2) & 0xcccccccc);
        x = ((x >> 4) & 0x0f0f0f0f) | ((x << 4) & 0xf0f0f0f0);
        x = ((x >> 8) & 0x00ff00ff) | ((x << 8) & 0xff00ff00);
        x = ((x >>16) & 0x0000ffff) | ((x <<16) & 0xffff0000);
        return x;
    }

    inline LL reverse_bits(LL x){
        x = ((x >> 1) & 0x5555555555555555LL) | ((x << 1) & 0xaaaaaaaaaaaaaaaaLL);
        x = ((x >> 2) & 0x3333333333333333LL) | ((x << 2) & 0xccccccccccccccccLL);
        x = ((x >> 4) & 0x0f0f0f0f0f0f0f0fLL) | ((x << 4) & 0xf0f0f0f0f0f0f0f0LL);
        x = ((x >> 8) & 0x00ff00ff00ff00ffLL) | ((x << 8) & 0xff00ff00ff00ff00LL);
        x = ((x >>16) & 0x0000ffff0000ffffLL) | ((x <<16) & 0xffff0000ffff0000LL);
        x = ((x >>32) & 0x00000000ffffffffLL) | ((x <<32) & 0xffffffff00000000LL);
        return x;
    }

    template<class T> inline bool odd(T x){return x&1;}
    template<class T> inline bool even(T x){return !odd(x);}
    template<class T> inline T low_bit(T x) {return x & -x;}
    template<class T> inline T high_bit(T x) {T p = low_bit(x);while (p != x) x -= p, p = low_bit(x);return p;}
    template<class T> inline T cover_bit(T x){T p = 1; while (p < x) p <<= 1;return p;}
    template<class T> inline int cover_idx(T x){int p = 0; while (_1(p) < x ) ++p; return p;}

    inline int clz(int x){return __builtin_clz(x);}
    inline int clz(LL x){return __builtin_clzll(x);}
    inline int ctz(int x){return __builtin_ctz(x);}
    inline int ctz(LL x){return __builtin_ctzll(x);}
    inline int lg2(int x){return !x ? -1 : 31 - clz(x);}
    inline int lg2(LL x){return !x ? -1 : 63 - clz(x);}
    inline int low_idx(int x){return !x ? -1 : ctz(x);}
    inline int low_idx(LL x){return !x ? -1 : ctz(x);}
    inline int high_idx(int x){return lg2(x);}
    inline int high_idx(LL x){return lg2(x);}
    inline int parity(int x){return __builtin_parity(x);}
    inline int parity(LL x){return __builtin_parityll(x);}
    inline int count_bits(int x){return __builtin_popcount(x);}
    inline int count_bits(LL x){return __builtin_popcountll(x);}

} using namespace BO;//}

// <<= '2. Number Theory .,//{
namespace NT{
#define gcd __gcd
    inline LL lcm(LL a, LL b){return a*b/gcd(a,b);}

    inline void INC(int &a, int b){a += b; if (a >= MOD) a -= MOD;}
    inline int sum(int a, int b){a += b; if (a >= MOD) a -= MOD; return a;}

    /* 模数两倍刚好超 int 时。
     inline int sum(uint a, int b){a += b; a %= MOD;if (a < 0) a += MOD; return a;}
     inline void INC(int &a, int b){a = sum(a, b);}
     */

    inline void DEC(int &a, int b){a -= b; if (a < 0) a += MOD;}
    inline int dff(int a, int b){a -= b; if (a < 0) a  += MOD; return a;}
    inline void MUL(int &a, int b){a = (LL)a * b % MOD;}
    //inline int pdt(int a, int b){return (LL)a * b % MOD;}
    inline int pdt(int x,int y) {
        int ret; __asm__ __volatile__ ("\tmull %ebx\n\tdivl %ecx\n":"=d"(ret):"a"(x),"b"(y),"c"(MOD));
        return ret;
    }

    inline int gcd(int m, int n, int &x, int &y){

        x = 1, y = 0; int xx = 0, yy = 1, q;

        while (1){
            q = m / n, m %= n;
            if (!m){x = xx, y = yy; return n;}
            DEC(x, pdt(q, xx)), DEC(y, pdt(q, yy));
            q = n / m, n %= m;
            if (!n) return m;
            DEC(xx, pdt(q, x)), DEC(yy, pdt(q, y));
        }
    }

    inline int sum(int a, int b, int c){return sum(a, sum(b, c));}
    inline int sum(int a, int b, int c, int d){return sum(sum(a, b), sum(c, d));}
    inline int pdt(int a, int b, int c){return pdt(a, pdt(b, c));}
    inline int pdt(int a, int b, int c, int d){return pdt(pdt(a, b), pdt(c, d));}

    inline int pow(int a, LL b){
        int c(1); while (b){
            if (b&1) MUL(c, a);
            MUL(a, a), b >>= 1;
        }
        return c;
    }

    template<class T> inline T pow(T a, LL b){
        T c(1); while (b){
            if (b&1) c *= a;
            a *= a, b >>= 1;
        }
        return c;
    }

    template<class T> inline T pow(T a, int b){
        return pow(a, (LL)b);
    }

    inline int _I(int b){
        int a = MOD, x1 = 0, x2 = 1, q; while (1){
            q = a / b, a %= b;
            if (!a) return x2;
            DEC(x1, pdt(q, x2));

            q = b / a, b %= a;
            if (!b) return x1;
            DEC(x2, pdt(q, x1));
        }
    }

    inline void DIV(int &a, int b){MUL(a, _I(b));}
    inline int qtt(int a, int b){return pdt(a, _I(b));}

    struct Int{
        int val;

        operator int() const{return val;}

        Int(int _val = 0):val(_val){
            val %= MOD; if (val < 0) val += MOD;
        }
        Int(LL _val):val(_val){
            _val %= MOD; if (_val < 0) _val += MOD;
            val = _val;
        }

        Int& operator +=(const int& rhs){INC(val, rhs);rTs;}
        Int operator +(const int& rhs) const{return sum(val, rhs);}
        Int& operator -=(const int& rhs){DEC(val, rhs);rTs;}
        Int operator -(const int& rhs) const{return dff(val, rhs);}
        Int& operator *=(const int& rhs){MUL(val, rhs);rTs;}
        Int operator *(const int& rhs) const{return pdt(val, rhs);}
        Int& operator /=(const int& rhs){DIV(val, rhs);rTs;}
        Int operator /(const int& rhs) const{return qtt(val, rhs);}
        Int operator-()const{return MOD-*this;}
    };

} using namespace NT;//}

//}

/** I/O Accelerator Interface .. **/ //{
#define g (c=getchar())
#define d isdigit(g)
#define p x=x*10+c-'0'
#define n x=x*10+'0'-c
#define pp l/=10,p
#define nn l/=10,n
template<class T> inline T& RD(T &x){
    char c;while(!d);x=c-'0';while(d)p;
    return x;
}
template<class T> inline T& RDD(T &x){
    char c;while(g,c!='-'&&!isdigit(c));
    if (c=='-'){x='0'-g;while(d)n;}
    else{x=c-'0';while(d)p;}
    return x;
}
inline DB& RF(DB &x){
    //scanf("%lf", &x);
    char c;while(g,c!='-'&&c!='.'&&!isdigit(c));
    if(c=='-')if(g=='.'){x=0;DB l=1;while(d)nn;x*=l;}
    else{x='0'-c;while(d)n;if(c=='.'){DB l=1;while(d)nn;x*=l;}}
    else if(c=='.'){x=0;DB l=1;while(d)pp;x*=l;}
    else{x=c-'0';while(d)p;if(c=='.'){DB l=1;while(d)pp;x*=l;}}
    return x;
}
#undef nn
#undef pp
#undef n
#undef p
#undef d
#undef g
inline char* RS(char *s){
    //gets(s);
    scanf("%s", s);
    return s;
}

LL last_ans; int Case; template<class T> inline void OT(const T &x){
    //printf("Case #%d: ", ++Case);
    //printf("%lld\n", x);
    //printf("%I64d\n", x);
    //printf("%.9f\n", x);
    //printf("%d\n", x);
    cout << x << endl;
    //last_ans = x;
}

//}/* .................................................................................................................................. */
//线段树 题意：正数插入，负数abs()位置删除 节点删除直接置为0就可
const int maxn = 1e6 + 5;
LL sumt[maxn<<2];
#define rson p<<1|1
#define lson p<<1
void ins(int p, int l, int r, int k){
    if (l == r) {
        sumt[p]++; return ;
    }
    int mid = l + r >> 1;
    if (k <= mid) ins(lson, l, mid, k);
    else ins(rson, mid + 1, r, k);

    sumt[p] = sumt[lson] + sumt[rson]; //pushup
}

void del(int p, int l, int r, int k){
    if (l == r) {sumt[p]--; return ;}
    int mid = l + r >> 1;
    if (sumt[lson] >= k) del(lson, l, mid, k);
    else del(rson, mid + 1, r, k - sumt[lson]);
    sumt[p] = sumt[lson] + sumt[rson];
}

int query(int p, int l, int r){
    if (l == r){
        return l;
    }
    int mid = l + r >> 1;
    if (sumt[lson] != 0) return query(lson, l, mid);
    if (sumt[rson] != 0) return query(rson, mid + 1, r);
}

int main(){
    int n, q; RD(n, q);
    for(int i = 1; i <= n; i++){
        int x; cin >> x; ins(1, 1, n, x);
    }
    for(int que = 1; que <= q; que++){
        int x; cin >> x;
        if (x > 0) ins(1, 1, n, x);
        else { del(1, 1, n, abs(x));}
    }
    if (sumt[1]!=0) cout << query(1, 1, n) << '\n';
    else cout << 0 << '\n';
}


# include <bits/stdc++.h>
# define ll long long
using namespace std;

void update(int fen[],int size,int id,int v)
{
    int n=size;
    for(;id<=n;id+=id&-id)
    fen[id]+=v;

}

int sum(int fen[],int id)
{int ret=0;
    for(;id;id-=id&-id)
      ret+=fen[id];

  return ret;}

int main()
{
   int n,q,num,k;

   cin>>n>>q;
    int  *fen;
    fen=(int *)malloc(1000005*sizeof(int));
    for(int i=0;i<=n;i++)
    {
        fen[i]=0;
    }
   for(int i=1;i<=n;i++)
   {
       cin>>num;
       update(fen,n,num,1);
   }

   for(int i=0;i<q;i++)
   {
       cin>>k;
       if(k>=0)
       {
           update(fen,n,k,1);
       }
       else
       {
           k=-1*k;
         int l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=l+r>>1;
         if(sum(fen,mid)>=k)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
     update(fen,n,ans,-1);

       }
   }

   if(sum(fen,n)==0)
   {
       cout<<0<<endl;
   }
   else
   {
        int l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=l+r>>1;
         if(sum(fen,mid)>=1)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
       cout<<ans<<endl;
   }

}


# include <bits/stdc++.h>
# define ll long long
using namespace std;

void update(int fen[],int size,int id,int v)
{
    int n=size;
    for(;id<=n;id+=id&-id)
    fen[id]+=v;

}

int sum(int fen[],int id)
{int ret=0;
    for(;id;id-=id&-id)
      ret+=fen[id];

  return ret;}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
   int n,q,num,k;

   cin>>n>>q;
    int  *fen;
    fen=(int *)malloc(1000005*sizeof(int));
    for(int i=0;i<=n;i++)
    {
        fen[i]=0;
    }
   for(int i=1;i<=n;i++)
   {
       cin>>num;
       update(fen,n,num,1);
   }

   for(int i=0;i<q;i++)
   {
       cin>>k;
       if(k>=0)
       {
           update(fen,n,k,1);
       }
       else
       {
           k=-1*k;
         int l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=l+r/2;
         if(sum(fen,mid)>=k)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
     update(fen,n,ans,-1);

       }
   }

   if(sum(fen,n)==0)
   {
       cout<<0<<endl;
   }
   else
   {
        int l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=l+r/2;
         if(sum(fen,mid)>=1)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
       cout<<ans<<endl;
   }

}


# include <bits/stdc++.h>
# define ll long long
using namespace std;

int main()
{
    int n,q,num,k;
    vector<int> v;
    cin>>n>>q;

   for(int i=0;i<n;i++)
   {
       cin>>num;
       v.push_back(num);
   }

   for(int i=0;i<q;i++)
   {
       cin>>k;
       if(k>=0)
       {
         v.insert(v.end(),k) ;
          sort(v.begin(),v.end());
       }
       else
       {

           k=-1*k;
           k=k-1;
           auto itr =v.begin()+k;
           v.erase(itr);
       }

   }
   if(v.empty())
       {
           cout<<0<<endl;
       }
       else
       {
           cout<<*v.begin()<<endl;
       }

}


# include <bits/stdc++.h>
# define ll long long
using namespace std;

void update(int fen[],int size,int id,int v)
{
    int n=size;
    for(;id<=n;id+=id&-id)
    fen[id]+=v;

}

int sum(int fen[],int id)
{int ret=0;
    for(;id;id-=id&-id)
      ret+=fen[id];

  return ret;}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
   int n,q,num,k;

   cin>>n>>q;
    int  *fen;
    fen=(int *)malloc(n+1*sizeof(int));
    for(int i=0;i<=n;i++)
    {
        fen[i]=0;
    }
   for(int i=1;i<=n;i++)
   {
       cin>>num;
       update(fen,n,num,1);
   }

   for(int i=0;i<q;i++)
   {
       cin>>k;
       if(k>=0)
       {
           update(fen,n,k,1);
       }
       else
       {
           k=-1*k;
         int l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=l+r>>1;
         if(sum(fen,mid)>=k)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
     update(fen,n,ans,-1);

       }
   }

   if(sum(fen,n)==0)
   {
       cout<<0<<endl;
   }
   else
   {
        int l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=l+r>>1;
         if(sum(fen,mid)>=1)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
       cout<<ans<<endl;
   }

}


# include <bits/stdc++.h>
# define ll long long
using namespace std;

int sum(int n,int arr[])
{
    int res=0;
    for(int i=0;i<n;i++)
    {
        res+=arr[i];
    }
    return res;
}
int findans(int k,int arr[],int n)
{
    int l=0,r=n-1,ans=n-1;
     while(l<=r)
                {
                    int mid=(l+r)/2;
                    if(sum(mid,arr)>=k)
                    {ans=mid,r=mid-1;
                    }
                    else
                    {
                        l=mid+1;
                    }

                }
                return ans;
}

int main()
{
    int n,q,num,k;

        cin>>n>>q;
         int *arr,*prefixsum;
         arr=(int *)malloc(n*sizeof(int));
         prefixsum=(int *)malloc(n*sizeof(int));
         for(int i=0;i<n;i++)
         {
             arr[i]=0;
         }
        for(int i=0;i<n;i++)
        {
            cin>>num;
            arr[num-1]++;
        }

        for(int i=0;i<q;i++)
        {
            cin>>k;
            if(k>0)
            {
               k=k-1;
               arr[k]++;
            }
            else
            {
                k=-1*k;
                int out=findans(k,arr,n);
                arr[out]=arr[out]-1;

            }
        }

       if(sum(n,arr)==0)
       {
           cout<<0<<endl;
       }
        else
        {
            cout<<findans(1,arr,n)<<endl;
        }

}


# include <bits/stdc++.h>
# define ll long long
using namespace std;

void update(int fen[],int size,int id,int v)
{
    int n=size;
    for(;id<=n;id+=id&-id)
    fen[id]+=v;

}

int sum(int fen[],int id)
{int ret=0;
    for(;id;id-=id&-id)
      ret+=fen[id];

  return ret;}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
   int n,q,num,k;

   cin>>n>>q;
    int  *fen;
    fen=(int *)malloc(1000005*sizeof(int));
    for(int i=0;i<=n;i++)
    {
        fen[i]=0;
    }
   for(int i=1;i<=n;i++)
   {
       cin>>num;
       update(fen,n,num,1);
   }

   for(int i=0;i<q;i++)
   {
       cin>>k;
       if(k>=0)
       {
           update(fen,n,k,1);
       }
       else
       {
           k=-1*k;
         ll l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=l+r/2;
         if(sum(fen,mid)>=k)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
     update(fen,n,ans,-1);

       }
   }

   if(sum(fen,n)==0)
   {
       cout<<0<<endl;
   }
   else
   {
        ll l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=l+r/2;
         if(sum(fen,mid)>=1)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
       cout<<ans<<endl;
   }

}


# include <bits/stdc++.h>
# define ll long long
using namespace std;

int main()
{
    int n,q,num,k;
    vector<int> v;
    cin>>n>>q;

   for(int i=0;i<n;i++)
   {
       cin>>num;
       v.push_back(num);
   }
   sort(v.begin(),v.end());
   for(int i=0;i<q;i++)
   {
       cin>>k;
       if(k>=0)
       {
         v.insert(v.end(),k) ;
       }
       else
       {

           k=-1*k;
           k=k-1;
           auto itr =v.begin()+k;
           v.erase(itr);
       }

   }
   if(v.empty())
       {
           cout<<0<<endl;
       }
       else
       {
           cout<<*v.begin()<<endl;
       }

}


# include <bits/stdc++.h>
# define ll long long
using namespace std;

void update(int fen[],int size,int id,int v)
{
    int n=size;
    for(;id<=n;id+=id&-id)
    fen[id]+=v;

}

int sum(int fen[],int id)
{int ret=0;
    for(;id;id-=id&-id)
      ret+=fen[id];

  return ret;}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
   int n,q,num,k;

   cin>>n>>q;
    int  *fen;
    fen=(int *)malloc(1000000*sizeof(int));
    for(int i=0;i<=n;i++)
    {
        fen[i]=0;
    }
   for(int i=1;i<=n;i++)
   {
       cin>>num;
       update(fen,n,num,1);
   }

   for(int i=0;i<q;i++)
   {
       cin>>k;
       if(k>=0)
       {
           update(fen,n,k,1);
       }
       else
       {
           k=-1*k;
         int l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=l+r>>1;
         if(sum(fen,mid)>=k)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
     update(fen,n,ans,-1);

       }
   }

   if(sum(fen,n)==0)
   {
       cout<<0<<endl;
   }
   else
   {
        int l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=l+r>>1;
         if(sum(fen,mid)>=1)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
       cout<<ans<<endl;
   }

}


# include <bits/stdc++.h>
# define ll long long
using namespace std;

void update(int *fen,int size,int id,int v)
{
    int n=size;
    for(;id<=n;id+=id&-id)
    fen[id]+=v;

}

int sum(int *fen,int id)
{int ret=0;
    for(;id;id-=id&-id)
      ret+=fen[id];

  return ret;}

 int  findans(int *fen,int k,int n)
 {
     int l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=l+r/2;
         if(sum(fen,mid)>=k)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
     return ans;
 }

int main()
{
   int n,q,num,k;

   cin>>n>>q;
    int *fen=new int[2*n];
   for(int i=1;i<=n;i++)
   {
       cin>>num;
       update(fen,n,num,1);
   }

   for(int i=0;i<q;i++)
   {
       cin>>k;
       if(k>=0)
       {
           update(fen,n,k,1);
       }
       else
       {
           k=-1*k;
            int x=findans(fen,k,n);
          update(fen,n,x,-1);

       }
   }

   if(sum(fen,n)==0)
   {
       cout<<0<<endl;
   }
   else
   {
       cout<<findans(fen,1,n)<<endl;
   }

}


# include <bits/stdc++.h>
# define ll long long
using namespace std;

void update(int fen[],int size,int id,int v)
{
    int n=size;
    for(;id<=n;id+=id&-id)
    fen[id]+=v;

}

int sum(int fen[],int id)
{int ret=0;
    for(;id;id-=id&-id)
      ret+=fen[id];

  return ret;}

int main()
{
   int n,q,num,k;

   cin>>n>>q;
    int  *fen;
    fen=(int *)malloc(n+1*sizeof(int));
    for(int i=0;i<=n;i++)
    {
        fen[i]=0;
    }
   for(int i=1;i<=n;i++)
   {
       cin>>num;
       update(fen,n,num,1);
   }

   for(int i=0;i<q;i++)
   {
       cin>>k;
       if(k>=0)
       {
           update(fen,n,k,1);
       }
       else
       {
           k=-1*k;
         int l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=l+r>>1;
         if(sum(fen,mid)>=k)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
     update(fen,n,ans,-1);

       }
   }

   if(sum(fen,n)==0)
   {
       cout<<0<<endl;
   }
   else
   {
        int l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=l+r>>1;
         if(sum(fen,mid)>=1)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
       cout<<ans<<endl;
   }

}


# include <bits/stdc++.h>
# define ll long long
using namespace std;

void update(int fen[],int size,int id,int v)
{
    int n=size;
    for(;id<=n;id+=id&-id)
    fen[id]+=v;

}

int sum(int fen[],int id)
{int ret=0;
    for(;id;id-=id&-id)
      ret+=fen[id];

  return ret;}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
   int n,q,num,k;

   cin>>n>>q;
    int  *fen;
    fen=(int *)malloc(1000005*sizeof(int));
    for(int i=0;i<=n;i++)
    {
        fen[i]=0;
    }
   for(int i=1;i<=n;i++)
   {
       cin>>num;
       update(fen,n,num,1);
   }

   for(int i=0;i<q;i++)
   {
       cin>>k;
       if(k>=0)
       {
           update(fen,n,k,1);
       }
       else
       {
           k=-1*k;
         int l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=l+r>>1;
         if(sum(fen,mid)>=k)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
     update(fen,n,ans,-1);

       }
   }

   if(sum(fen,n)==0)
   {
       cout<<0<<endl;
   }
   else
   {
        int l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=l+r>>1;
         if(sum(fen,mid)>=1)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
       cout<<ans<<endl;
   }

}


# include <bits/stdc++.h>
# define ll long long
using namespace std;

int main()
{
    int n,q,num,k;
    vector<int> v;
    cin>>n>>q;

   for(int i=0;i<n;i++)
   {
       cin>>num;
       v.push_back(num);
   }

   for(int i=0;i<q;i++)
   {
       cin>>k;
       if(k>=0)
       {
         v.insert(v.end(),k) ;
       }
       else
       {
           sort(v.begin(),v.end());
           k=-1*k;
           k=k-1;
           auto itr =v.begin()+k;
           v.erase(itr);
       }

   }
   if(v.empty())
       {
           cout<<0<<endl;
       }
       else
       {
           cout<<*v.begin()<<endl;
       }

}


# include <bits/stdc++.h>
# define ll long long
using namespace std;

void update(ll fen[],ll size,ll id,ll v)
{
    ll n=size;
    for(;id<=n;id+=id&-id)
    fen[id]+=v;

}

ll sum(ll fen[],ll id)
{ll ret=0;
    for(;id;id-=id&-id)
      ret+=fen[id];

  return ret;}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
   ll n,q,num,k;

   cin>>n>>q;
    ll  *fen;
    fen=(ll *)malloc(1000005*sizeof(ll));
    for(int i=0;i<=n;i++)
    {
        fen[i]=0;
    }
   for(int i=1;i<=n;i++)
   {
       cin>>num;
       update(fen,n,num,1);
   }

   for(int i=0;i<q;i++)
   {
       cin>>k;
       if(k>=0)
       {
           update(fen,n,k,1);
       }
       else
       {
           k=-1*k;
         ll l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=(l+r)/2;
         if(sum(fen,mid)>=k)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
     update(fen,n,ans,-1);

       }
   }

   if(sum(fen,n)==0)
   {
       cout<<0<<endl;
   }
   else
   {
        ll l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=(l+r)/2;
         if(sum(fen,mid)>=1)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
       cout<<ans<<endl;
   }

}


# include <bits/stdc++.h>
# define ll long long
using namespace std;

void update(int *fen,int size,int id,int v)
{
    int n=size;
    for(;id<=n;id+=id&-id)
    fen[id]+=v;

}

int sum(int *fen,int id)
{int ret=0;
    for(;id;id-=id&-id)
      ret+=fen[id];

  return ret;}

 int  findans(int *fen,int k,int n)
 {
     int l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=l+r/2;
         if(sum(fen,mid)>=k)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
     return ans;
 }

int main()
{
   int n,q,num,k;

   cin>>n>>q;
    int *fen=new int[n+1];
   for(int i=1;i<=n;i++)
   {
       cin>>num;
       update(fen,n,num,1);
   }

   for(int i=0;i<q;i++)
   {
       cin>>k;
       if(k>=0)
       {
           update(fen,n,k,1);
       }
       else
       {
           k=-1*k;
            int x=findans(fen,k,n);
          update(fen,n,x,-1);

       }
   }

   if(sum(fen,n)==0)
   {
       cout<<0<<endl;
   }
   else
   {
       cout<<findans(fen,1,n)<<endl;
   }

}


# include <bits/stdc++.h>
# define ll long long
using namespace std;

void update(int *fen,int size,int id,int v)
{
    int n=size;
    for(;id<=n;id+=id&-id)
    fen[id]+=v;

}

int sum(int *fen,int id)
{int ret=0;
    for(;id;id-=id&-id)
      ret+=fen[id];

  return ret;}

 int  findans(int *fen,int k,int n)
 {
     int l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=l+r/2;
         if(sum(fen,mid)>=k)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
     return ans;
 }

int main()
{
   int n,q,num,k;

   cin>>n>>q;
    int  fen[100005]={0};
   for(int i=1;i<=n;i++)
   {
       cin>>num;
       update(fen,n,num,1);
   }

   for(int i=0;i<q;i++)
   {
       cin>>k;
       if(k>=0)
       {
           update(fen,n,k,1);
       }
       else
       {
           k=-1*k;
            int x=findans(fen,k,n);
          update(fen,n,x,-1);

       }
   }

   if(sum(fen,n)==0)
   {
       cout<<0<<endl;
   }
   else
   {
       cout<<findans(fen,1,n)<<endl;
   }

}


# include <bits/stdc++.h>
# define ll long long
using namespace std;

int main()
{
    int n,q,num,k;
    multiset<int> ms;
    cin>>n>>q;

   for(int i=0;i<n;i++)
   {
       cin>>num;
       ms.insert(num);
   }

   for(int i=0;i<q;i++)
   {
       cin>>k;
       if(k>=0)
       {
          ms.insert(k);
       }
       else
       {
           k=-1*k;
           k=k-1;
           auto itr=ms.begin();
           while(k--)
           {
             itr++;
           }
           ms.erase(*itr);
       }

   }
   if(ms.empty())
       {
           cout<<0<<endl;
       }
       else
       {
           cout<<*ms.begin()<<endl;
       }

}


# include <bits/stdc++.h>
# define ll long long
using namespace std;

void update(int fen[],int size,int id,int v)
{
    int n=size;
    for(;id<=n;id+=id&-id)
    fen[id]+=v;

}

int sum(int fen[],int id)
{int ret=0;
    for(;id;id-=id&-id)
      ret+=fen[id];

  return ret;}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
   int n,q,num,k;

   cin>>n>>q;
    int  *fen;
    fen=(int *)malloc(10000005*sizeof(int));
    for(int i=0;i<=n;i++)
    {
        fen[i]=0;
    }
   for(int i=1;i<=n;i++)
   {
       cin>>num;
       update(fen,n,num,1);
   }

   for(int i=0;i<q;i++)
   {
       cin>>k;
       if(k>=0)
       {
           update(fen,n,k,1);
       }
       else
       {
           k=-1*k;
         int l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=l+r>>1;
         if(sum(fen,mid)>=k)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
     update(fen,n,ans,-1);

       }
   }

   if(sum(fen,n)==0)
   {
       cout<<0<<endl;
   }
   else
   {
        int l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=l+r>>1;
         if(sum(fen,mid)>=1)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
       cout<<ans<<endl;
   }

}


# include <bits/stdc++.h>
# define ll long long
using namespace std;

void update(int fen[],int size,int id,int v)
{
    int n=size;
    for(;id<=n;id+=id&-id)
    fen[id]+=v;

}

int sum(int fen[],int id)
{int ret=0;
    for(;id;id-=id&-id)
      ret+=fen[id];

  return ret;}

int main()
{
   int n,q,num,k;

   cin>>n>>q;
    int  *fen;
    fen=(int *)malloc(2*n*sizeof(int));
    for(int i=0;i<=n;i++)
    {
        fen[i]=0;
    }
   for(int i=1;i<=n;i++)
   {
       cin>>num;
       update(fen,n,num,1);
   }

   for(int i=0;i<q;i++)
   {
       cin>>k;
       if(k>=0)
       {
           update(fen,n,k,1);
       }
       else
       {
           k=-1*k;
         int l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=l+r>>1;
         if(sum(fen,mid)>=k)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
     update(fen,n,ans,-1);

       }
   }

   if(sum(fen,n)==0)
   {
       cout<<0<<endl;
   }
   else
   {
        int l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=l+r>>1;
         if(sum(fen,mid)>=1)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
       cout<<ans<<endl;
   }

}


# include <bits/stdc++.h>
# define ll long long
using namespace std;

void update(int fen[],int size,int id,int v)
{
    int n=size;
    for(;id<=n;id+=id&-id)
    fen[id]+=v;

}

int sum(int fen[],int id)
{int ret=0;
    for(;id;id-=id&-id)
      ret+=fen[id];

  return ret;}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
   int n,q,num,k;

   cin>>n>>q;
    int  *fen;
    fen=(int *)malloc(10000000*sizeof(int));
    for(int i=0;i<=n;i++)
    {
        fen[i]=0;
    }
   for(int i=1;i<=n;i++)
   {
       cin>>num;
       update(fen,n,num,1);
   }

   for(int i=0;i<q;i++)
   {
       cin>>k;
       if(k>=0)
       {
           update(fen,n,k,1);
       }
       else
       {
           k=-1*k;
         int l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=l+r>>1;
         if(sum(fen,mid)>=k)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
     update(fen,n,ans,-1);

       }
   }

   if(sum(fen,n)==0)
   {
       cout<<0<<endl;
   }
   else
   {
        int l=1,r=n,ans,mid;
     while(l<=r)
     {
         mid=l+r>>1;
         if(sum(fen,mid)>=1)
         {
             r=mid-1;
            ans=mid;
         }
         else
         {
             l=mid+1;
         }

     }
       cout<<ans<<endl;
   }

}


#include<bits/stdc++.h>
using namespace std;
#define int long long
#define double long double
const int N =1e6+1;
int test=1;
int n,a[N],q,f[N],num[N];
void up(int x,int val)
{
    for(;x<=N;x+=x&-x)
        f[x]+=val;
}
int get(int x)
{
    int sum=0;
    for(;x>=1;x-=x&-x)
    {
        sum+=f[x];
    }
    return sum;
}
int era(int x)
{
    int ans ;
    int dau=1;int cuoi=n;
    while(dau<=cuoi)
    {
        int mid=(dau+cuoi)>>1;
        if(get(mid)>=x)
        {
            ans=mid;
            cuoi=mid-1;
        }
        else dau=mid+1;
    }
    return ans;
}
void In()
{
    cin>>n>>q;
    for(int i=1;i<=n;i++)
    {
        cin>>a[i];
    }
}
void Solve()
{   memset(f,0,sizeof(f));
    memset(num,0,sizeof(num));
    for(int i=1;i<=n;i++)
        up(a[i],1),num[a[i]]=1;
    for(int i=1;i<=q;i++)
    {
        int k;
        cin>>k;
        if(k>=1)
        {
            up(k,1);
            num[k]++;
        }
        else {
            k=-k;
            int t=era(k);
            up(t,-1);
            num[t]--;
        }
    }
    for(int i=1;i<=N;i++)
        if(num[i]>0)
    {
        cout<<i;
        exit(0);
    }
    cout<<0;
}
#undef int
int main()
{   ios::sync_with_stdio(false);
    cin.tie(0);
    if(fopen("trash.inp","r"))
        freopen("trash.inp","r",stdin);
    while(test--)
    {
        In();
        Solve();
    }
}


#include<bits/stdc++.h>
using namespace std;
#define int long long
#define double long double
const int N =1e6+1;
int test=1;
int n,a[N],q,f[N],num[N];
void up(int x,int val)
{
    for(;x<=N;x+=x&-x)
        f[x]+=val;
}
int get(int x)
{
    int sum=0;
    for(;x>=1;x-=x&-x)
    {
        sum+=f[x];
    }
    return sum;
}
int era(int x)
{
    int ans ;
    int dau=1;int cuoi=n;
    while(dau<=cuoi)
    {
        int mid=(dau+cuoi)>>1;
        if(get(mid)>=x)
        {
            ans=mid;
            cuoi=mid-1;
        }
        else dau=mid+1;
    }
    return ans;
}
void In()
{
    cin>>n>>q;
    for(int i=1;i<=n;i++)
    {
        cin>>a[i];
    }
}
void Solve()
{   memset(f,0,sizeof(f));
    memset(num,0,sizeof(num));
    for(int i=1;i<=n;i++)
        up(a[i],1),num[a[i]]=1;
    for(int i=1;i<=q;i++)
    {
        int k;
        cin>>k;
        if(k>=1)
        {
            up(k,1);
            num[k]++;
        }
        else {
            k=-k;
            int t=era(k);
            up(t,-1);
            num[t]--;
            cout<<t<<' '<<num[t]<<endl;
        }
    }
    for(int i=1;i<=N;i++)
        if(num[i]>0)
    {
        cout<<i<<' '<<num[i];
        exit(0);
    }
    cout<<0;
}
#undef int
int main()
{   ios::sync_with_stdio(false);
    cin.tie(0);
    if(fopen("trash.inp","r"))
        freopen("trash.inp","r",stdin);
    while(test--)
    {
        In();
        Solve();
    }
}


#include<bits/stdc++.h>
using namespace std;
#define double long double
const int N =1e6+1;
int test=1;
int n,a[N],q,f[N],num[N];
void up(int x,int val)
{
    for(;x<=n;x+=x&-x)
        f[x]+=val;
}
int get(int x)
{
    int sum=0;
    for(;x>=1;x-=x&-x)
    {
        sum+=f[x];
    }
    return sum;
}
int era(int x)
{
    int ans =-1;
    int dau=1;int cuoi=n;
    while(dau<=cuoi)
    {
        int mid=(dau+cuoi)>>1;
        if(get(mid)>=x)
        {
            ans=mid;
            cuoi=mid-1;
        }
        else dau=mid+1;
    }
    return ans;
}
void In()
{
    cin>>n>>q;
    for(int i=1;i<=n;i++)
    {
        cin>>a[i];
    }
}
void Solve()
{   memset(f,0,sizeof(f));
    memset(num,0,sizeof(num));
    for(int i=1;i<=n;i++)
        up(a[i],1),num[a[i]]=1;
    for(int i=1;i<=q;i++)
    {
        int k;
        cin>>k;
        if(k>=1)
        {
            up(k,1);
            num[k]++;
        }
        else {
            k=-k;
            int t=era(k);
            if(t==-1)
            {
                continue;
            }
            up(t,-1);
            num[t]--;
            //cout<<t<<' '<<num[t]<<endl;
        }
    }
    for(int i=1;i<=n;i++)
        if(num[i]>0)
    {
        cout<<i;//<<' '<<num[i];
        exit(0);
    }
    puts("0");
}
#undef int
int main()
{   ios::sync_with_stdio(false);
    cin.tie(0);
    if(fopen("trash.inp","r"))
        freopen("trash.inp","r",stdin);
    while(test--)
    {
        In();
        Solve();
    }
}


#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
typedef tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
int n;
const int N =1e6+9;
int a[N],q;
signed main() {
    if(fopen("trash.inp","r"))
        freopen("trash.inp","r",stdin);
    ordered_set s;
    cin>>n>>q;
    for(int i=1;i<=n;i++)
         cin>>a[i],s.insert(a[i]);
    for(int i=1;i<=q;i++)
    {
        int k;
        cin>>k;
        if(k>=1)
        {
            s.insert(k);
        }
        else {
            k=-k;
            auto it=s.find_by_order(k-1);
            s.erase(it);
        }
    }
    if(s.empty())
    cout<<0;
    else {
            cout<<*(s.begin())<<' ';
    }
}


#include<bits/stdc++.h>
using namespace std;
#define int long long
#define double long double
const int N =1e6+9;
int test=1;
int n,a[N],q,f[N],num[N];
void up(int x,int val)
{
    for(;x<=N;x+=x&-x)
        f[x]+=val;
}
int get(int x)
{
    int sum=0;
    for(;x>=1;x-=x&-x)
    {
        sum+=f[x];
    }
    return sum;
}
int era(int x)
{
    int ans ;
    int dau=1;int cuoi=n;
    while(dau<=cuoi)
    {
        int mid=(dau+cuoi)>>1;
        if(get(mid)>=x)
        {
            ans=mid;
            cuoi=mid-1;
        }
        else dau=mid+1;
    }
    return ans;
}
void In()
{
    cin>>n>>q;
    for(int i=1;i<=n;i++)
    {
        cin>>a[i];
    }
}
void Solve()
{   memset(f,0,sizeof(f));
    for(int i=1;i<=n;i++)
        up(a[i],1),num[a[i]]=1;
    for(int i=1;i<=q;i++)
    {
        int k;
        cin>>k;
        if(k>=1)
        {
            up(k,1);
            num[k]++;
        }
        else {
            k=-k;
            int t=era(k);
            up(t,-1);
            num[t]--;
        }
    }
    for(int i=1;i<=N;i++)
        if(num[i]>0)
    {
        cout<<i;
        return ;
    }
    cout<<0;
}
#undef int
int main()
{
    if(fopen("trash.inp","r"))
        freopen("trash.inp","r",stdin);
    while(test--)
    {
        In();
        Solve();
    }
}


#include<bits/stdc++.h>
using namespace std;
#define double long double
const int N =1e6+1;
int test=1;
int n,a[N],q,f[N],num[N];
void up(int x,int val)
{
    for(;x<=n;x+=x&-x)
        f[x]+=val;
}
int get(int x)
{
    int sum=0;
    for(;x>=1;x-=x&-x)
    {
        sum+=f[x];
    }
    return sum;
}
int era(int x)
{
    int ans =-1;
    int dau=1;int cuoi=n;
    while(dau<=cuoi)
    {
        int mid=(dau+cuoi)>>1;
        if(get(mid)>=x)
        {
            ans=mid;
            cuoi=mid-1;
        }
        else dau=mid+1;
    }
    return ans;
}
void In()
{
    cin>>n>>q;
    for(int i=1;i<=n;i++)
    {
        cin>>a[i];
    }
}
void Solve()
{   memset(f,0,sizeof(f));
    memset(num,0,sizeof(num));
    for(int i=1;i<=n;i++)
        up(a[i],1),num[a[i]]=1;
    for(int i=1;i<=q;i++)
    {
        int k;
        cin>>k;
        if(k>=1)
        {
            up(k,1);
            num[k]++;
        }
        else {
            k=-k;
            int t=era(k);
            up(t,-1);
            num[t]--;
            //cout<<t<<' '<<num[t]<<endl;
        }
    }
    for(int i=1;i<=n;i++)
        if(num[i]>0)
    {
        cout<<i;//<<' '<<num[i];
        exit(0);
    }
    puts("0");
}
#undef int
int main()
{   ios::sync_with_stdio(false);
    cin.tie(0);
    if(fopen("trash.inp","r"))
        freopen("trash.inp","r",stdin);
    while(test--)
    {
        In();
        Solve();
    }
}


#include<bits/stdc++.h>
using namespace std;
#define int long long
#define double long double
const int N =1e6+1;
int test=1;
int n,a[N],q,f[N],num[N];
void up(int x,int val)
{
    for(;x<=n;x+=x&-x)
        f[x]+=val;
}
int get(int x)
{
    int sum=0;
    for(;x>=1;x-=x&-x)
    {
        sum+=f[x];
    }
    return sum;
}
int era(int x)
{
    int ans ;
    int dau=1;int cuoi=n;
    while(dau<=cuoi)
    {
        int mid=(dau+cuoi)>>1;
        if(get(mid)>=x)
        {
            ans=mid;
            cuoi=mid-1;
        }
        else dau=mid+1;
    }
    return ans;
}
void In()
{
    cin>>n>>q;
    for(int i=1;i<=n;i++)
    {
        cin>>a[i];
    }
}
void Solve()
{   memset(f,0,sizeof(f));
    memset(num,0,sizeof(num));
    for(int i=1;i<=n;i++)
        up(a[i],1),num[a[i]]=1;
    for(int i=1;i<=q;i++)
    {
        int k;
        cin>>k;
        if(k>=1)
        {
            up(k,1);
            num[k]++;
        }
        else {
            k=-k;
            int t=era(k);
            up(t,-1);
            num[t]--;
            //cout<<t<<' '<<num[t]<<endl;
        }
    }
    for(int i=1;i<=n;i++)
        if(num[i]>0)
    {
        cout<<i;//<<' '<<num[i];
        exit(0);
    }
    cout<<0;
}
#undef int
int main()
{   ios::sync_with_stdio(false);
    cin.tie(0);
    if(fopen("trash.inp","r"))
        freopen("trash.inp","r",stdin);
    while(test--)
    {
        In();
        Solve();
    }
}


#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#define int long long
using namespace std;
using namespace __gnu_pbds;
typedef tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
int n;
const int N =1e6+9;
int a[N],q;
signed main() {
    if(fopen("trash.inp","r"))
        freopen("trash.inp","r",stdin);
    ordered_set s;
    cin>>n>>q;
    for(int i=1;i<=n;i++)
         cin>>a[i],s.insert(a[i]);
    for(int i=1;i<=q;i++)
    {
        int k;
        cin>>k;
        if(k>=0)
        {
            s.insert(k);
        }
        else {
            k=-k;
            auto it=s.find_by_order(k-1);
            s.erase(it);
        }
    }
    if(s.empty())
    cout<<0;
    else {
            cout<<*(s.begin());
    }
}