Formula 1 officials decided to introduce new competition. Cars are replaced by space ships and number of points awarded can differ per race.

Given the current ranking in the competition and points distribution for the next race, your task is to calculate the best possible ranking for a given astronaut after the next race. It's guaranteed that given astronaut will have unique number of points before the race.

Input

The first line contains two integer numbers N (1 ≤ N ≤ 200000) representing number of F1 astronauts, and current position of astronaut D (1 ≤ D ≤ N) you want to calculate best ranking for (no other competitor will have the same number of points before the race).

The second line contains N integer numbers S_k (0 ≤ S_k ≤ 10^8, k=1...N), separated by a single space, representing current ranking of astronauts. Points are sorted in non-increasing order.

The third line contains N integer numbers P_k (0 ≤ P_k ≤ 10^8, k=1...N), separated by a single space, representing point awards for the next race. Points are sorted in non-increasing order, so winner of the race gets the maximum number of points.

Output

Output contains one integer number — the best possible ranking for astronaut after the race. If multiple astronauts have the same score after the race, they all share the best ranking.

Example

Input

4 3
50 30 20 10
15 10 7 3


Output

2

Note

If the third ranked astronaut wins the race, he will have 35 points. He cannot take the leading position, but he can overtake the second position if the second ranked astronaut finishes the race at the last position.
//    A Computer is Like a mischievous genie.
//    It will give you exactly what you ask for,
//    but not always what you want
//    A code by Rahul Verma


import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.PriorityQueue;
import java.util.Queue;
import java.util.StringTokenizer;
import java.util.TreeMap;


public class Main {


    static class Clock {

        protected long start, stop;

        public void start() {
            start = System.currentTimeMillis();
        }

        public void stop() {
            stop = System.currentTimeMillis();
        }

        public String getTime() {
            return ((stop - start) + " ms");
        }
    }


    public static PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out));

    static class FastReader {

        BufferedReader br;
        StringTokenizer st;

        public FastReader() {
            br = new BufferedReader(new
                InputStreamReader(System.in));
        }

        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

        long nextLong() {
            return Long.parseLong(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        String[] nextSArray() {
            String sr[] = null;
            try {
                sr = br.readLine().trim().split(" ");
            } catch (IOException e) {
                e.printStackTrace();
            }
            return sr;
        }

        String nextLine() {
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }

            return str;
        }
    }


    static long powmodulo(long a, long p) {
        if (p == 0) {
            return 1 % mod;
        }
        if (p == 1) {
            return a % mod;
        }
        long ans = 1;
        while (p > 0) {
            if ((p & 1) > 0) {
                ans = (ans * a) % mod;
            }
            a = (a * a) % mod;
            p = p >> 1;
        }
        return ans % mod;
    }


    static long mod = 1000000007;

    static long gcd(long a, long b) {
        if (a == 0) {
            return b;
        }
        return gcd(b % a, a);
    }

    static long fast_powerNumbers(long a, long n) {
        if (n == 1) {
            return a;
        }
        long ans = fast_powerNumbers(a, n / 2);
        if (n % 2 == 0) {
            return (ans * ans);
        } else {
            return ((ans * ans) * (a));
        }
    }


    static void dfs_helper(int[][] arr, int i, int j, int team, int n, int m) {
        arr[i][j] = team;
        if (i - 1 >= 0 && arr[i - 1][j] == 1) {
            dfs(arr, i - 1, j, team, n, m);
        }
        if (j - 1 >= 0 && arr[i][j - 1] == 1) {
            dfs(arr, i, j - 1, team, n, m);
        }
        if (i + 1 < n && arr[i + 1][j] == 1) {
            dfs(arr, i + 1, j, team, n, m);
        }
        if (j + 1 < m && arr[i][j + 1] == 1) {
            dfs(arr, i, j + 1, team, n, m);
        }

    }

    static void dfs(int[][] arr, int i, int j, int team, int n, int m) {
        dfs_helper(arr, i, j, team, n, m);

    }

    static int parent[];
    static int rank[];

    static int find(int i) {
        if (parent[i] == -1) {
            parent[i] = i;
            return i;
        }

        if (parent[i] == i) {
            return i;
        } else {
            parent[i] = find(parent[i]);
        }
        return parent[i];

    }

    static void unite(int s1, int s2) {

        if (rank[s1] > rank[s2]) {
            parent[s2] = s1;
            rank[s1] += rank[s2];
        } else {
            parent[s1] = s2;
            rank[s2] += rank[s1];
        }
    }


    public static long arr[];

//    static void seive(int n) {
//        arr = new int[n + 1];
//        arr[0] = arr[1] = 1;
//        for (int i = 4; i <= n; i = i + 2) {
//            arr[i] = 1;
//        }
//        for (int i = 3; i * i <= n; i = i + 2) {
//            if (arr[i] == 0) {
//                for (int j = i * i; j <= n; j = j + i) {
//                    arr[j] = 1;
//                }
//
//            }
//        }
//    }




    static int a,b,c;

    public static void main(String[] args) throws Exception {
        FastReader sc = new FastReader();

        Clock clock = new Clock();
        clock.start();
//        int t1 =sc.nextInt();
//
//        for (int t = 0; t <t1; t++) {
//
//
//        }
//        out.close();
        int n=sc.nextInt();
        int d=sc.nextInt()-1;
        long point=0;
        ArrayList<Long>al=new ArrayList<>();
        ArrayList<Long>al2=new ArrayList<>();

        for (int i = 0; i < n; i++) {
            al.add(sc.nextLong());
        }
        point+=al.get(d);
        point+=sc.nextLong();
        for (int i = 1; i < n; i++) {
            al2.add(sc.nextLong());
        }
        int a=0;
        int b=n-2;
        int rank=1;
        for (int i = 0; i < n; i++) {
            if(i==d)
                continue;
            if(al.get(i)+al2.get(b)>point)
            {
                //System.out.println(al.get(i)+al2.get(a));
                ++rank;
                ++a;

            }
            else
            {
                --b;
            }
        }
        System.out.println(rank);

}}

class trio{
    long rs;int egg;int choco;
    trio(long rs,int egg,int choco)
    {
        this.rs=rs;
        this.egg=egg;
        this.choco=choco;
    }
}

class Pair{

    int a,b;
    Pair(int a,int b)
    {
        this.a=a;
        this.b=b;
    }
}
class DSU
{
    int parent[];
    int rank[];
    long arr[] = Main.arr;
    long sum[] ;
    DSU(int n)
    {
        this.parent=new int[n];
        this.rank=new int[n];
        sum=new long[n];
        Arrays.fill(parent,-1);
        Arrays.fill(rank,1);
        for (int i = 0; i <n ; i++) {
            sum[i]=arr[i];
        }
    }

    int find(int s1)
    {
        if(parent[s1]==-1)
            return s1;
        return parent[s1]=find(parent[s1]);
    }

    void unite(int s1,int s2)
    {
        int p1=this.find(s1);
        int p2=this.find(s2);
        if(p1==p2)
            return;
        if(rank[p1]>rank[p2])
        {
            parent[p2]=p1;
            rank[p1]+=rank[p2];
           // System.out.println(arr[p2]);

            sum[p1]+=sum[p2];
            //sum[p2]+=sum[p1];

        }
        else
        {
            parent[p1]=p2;
            rank[p2]+=rank[p1];
            //System.out.println(arr[p1]);
            sum[p2]+=sum[p1];
            //sum[p1]+=sum[p2];
        }
    }


}

class Graph {

    HashMap<Integer, ArrayList<Integer>> hm;

    Graph() {
        hm = new HashMap<>();
    }

    Graph(int n) {

        hm = new HashMap<>();
        for (int i = 0; i < n; i++) {
            hm.put(i, new ArrayList<Integer>());
        }
    }

    // function for adding an edge.................................................
    public void addEdge(int a, int b, boolean isDir) {
        if (isDir) {
            if (hm.containsKey(a)) {
                hm.get(a).add(b);
            } else {
                hm.put(a, new ArrayList<>(Arrays.asList(b)));
            }
        } else {
            if (hm.containsKey(a)) {
                hm.get(a).add(b);
            } else if (!hm.containsKey(a)) {
                hm.put(a, new ArrayList<>(Arrays.asList(b)));
            }

            if (hm.containsKey(b)) {
                hm.get(b).add(a);
            } else if (!hm.containsKey(b)) {
                hm.put(b, new ArrayList<>(Arrays.asList(a)));
            }
        }
    }


}

// out.println(al.toString().replaceAll("[\\[|\\]|,]",""));

