#include<iostream>
#include<cstdio>
#include<algorithm>
#include<functional>
#include<climits>
#include<stack>
#include<queue>
#include<cmath>
#define int long long
#define INF 100000000000
#define EPS 0.0000000001

using namespace std;

signed main() {
	int n, m;
	int a[1010], b[1010];
	int ans[1010] = { 0 };
	int vote = -1;
	cin >> n >> m;
	for (int i = 0; i < n; i++) {
		cin >> a[i];
	}
	for (int i = 0; i < m; i++) {
		cin >> b[i];
	}
	for (int i = 0; i < m; i++) {
		for (int j = 0; j < n; j++) {
			if (a[j] <= b[i]) {
				ans[j]++;
				//cout << j + 1 << endl;
				break;
			}
		}
	}
	int temp = 0;
	for (int i = 0; i < n; i++) {
		//for (int j = 0; j < n; j++) {
			//cout << ans[i] << " " << endl;
			if (temp < ans[i]) {
				//cout << "[" << i << "]" << endl;
				temp = ans[i];
				vote = i;
			}
		//}
	}
	cout << vote + 1 << endl;
	return 0;
}
#include <bits/stdc++.h>

using namespace std;

inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}
template<class T> inline T sqr(T x) {return x*x;}

typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<string> vs;
typedef pair<int, int> pii;
typedef long long ll;

#define all(a)  (a).begin(),(a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define pb push_back
#define mp make_pair
#define each(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define exist(s,e) ((s).find(e)!=(s).end())
#define range(i,a,b) for(int i=(a);i<(b);++i)
#define rep(i,n)  range(i,0,n)
#define clr(a,b) memset((a), (b) ,sizeof(a))
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

const double eps = 1e-10;
const double pi  = acos(-1.0);
const ll INF =1LL << 62;
const int inf =1 << 24;

int main(void){
    for(int n, m; cin >> n >> m;){
        vi a(n); for(auto && aa : a) cin >> aa;
        vi b(m); for(auto && bb : b) cin >> bb;

        vi v(n);
        for(int bb : b){
            rep(i, n){
                if(a[i] <= bb){
                    v[i]++;
                    break;
                }
            }
        }

        cout << max_element(all(v)) - v.begin() + 1 << endl;
    }

	return 0;
}