#include<iostream>
#include<sstream>
#include<algorithm>
#include<climits>
#include<cmath>
#include<cstdio>
#include<cstdlib>
#include<ctime>
#include<cfloat>
#include<functional>
#include<map>
#include<string>
#include<cstring>
#include<vector>
#include<queue>
#include<stack>
#include<deque>
#include<set>
#include<bitset>
#include<list>
#include<numeric>
#include<complex>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> i_i;
typedef pair<long long, int> ll_i;
typedef pair<double, int> d_i;
typedef pair<long long, long long> ll_ll;
typedef pair<double, double> d_d;
typedef vector<int> Vint;

#define PI 3.141592653589793238462643383279
#define mod 1000000007LL
#define rep(i, n) for(i = 0;i < n;++i)
#define rep1(i, n) for(i = 1;i < n;++i)
#define rep2d(i, j, n) for(i = 0;i < n;++i)for(j = i + 1;j < n;++j)
#define per(i, n) for(i = n - 1;i > -1;--i)
#define int(x) int x; scanf("%d",&x)
#define int2(x, y) int x, y; scanf("%d%d",&x, &y)
#define int3(x, y, z) int x, y, z; scanf("%d%d%d",&x, &y, &z)
#define int4(v, x, y, z) int v, x, y, z; scanf("%d%d%d%d", &v, &x, &y, &z)
#define int5(v, w, x, y, z) int v, w, x, y, z; scanf("%d%d%d%d%d", &v, &w, &x, &y, &z)
#define scn(n, a) rep(i, n)cin >> a[i]
#define sc2n(n, a, b) rep(i, n)cin >> a[i] >> b[i]
#define pri(x) cout << x << "\n"
#define pri2(x, y) cout << x << " " << y << "\n"
#define pri3(x, y, z) cout << x << " " << y << " " << z << "\n"
#define pb push_back
#define mp make_pair
#define all(a) (a).begin(),(a).end()
#define endl "\n"
#define kabe puts("---------------------------")
#define kara puts("")
#define debug(x) cout << " --- " << x << "\n"
#define debug2(x, y) cout << " --- " << x << " " << y << "\n"
#define debug3(x, y, z) cout << " --- " << x << " " << y << " " << z << "\n"
#define X first
#define Y second
#define eps 0.0001
#define prid(x) printf("%.15lf\n", x)


signed main(void){
  int i, j, k;
  for(int testcase = 0;testcase >= 0;testcase++){
    int2(n, m);
    int a[n], cnt[n];
    scn(n, a);
    rep(i, n)cnt[i] = 0;

    rep(i, m){
      int(b);
      rep(j, n)if(b >= a[j]){
        cnt[j]++; break;
      }
    }

    int ma = 0;
    rep1(i, n)if(cnt[ma] < cnt[i])ma = i;
    pri(ma + 1);


/*/

//*/ break;
  }
  return 0;
}
#include<iostream>
using namespace std;
int main(void)
{
    int n,m,mo[1001],bo[1001],ans[1001],A=0,i2;
    cin>>n>>m;
    for(int i=0;i<n;i++){
        ans[i]=0;
    }
    for(int i=0;i<n;i++){
        cin>>mo[i];
    }
    for(int i=0;i<m;i++){
        cin>>bo[i];
    }
    for(int i=0;i<m;i++){
        for(int j=0;j<n;j++){
            if(mo[j]<=bo[i]){
                i2=j;
                break;
            }

        }
        ans[i2]+=1;
    }
    for(int i=0;i<n;i++){
        if(A<ans[i]){
            A=ans[i];
            i2=i;
        }
    }
    cout<<i2+1<<"\n";
}