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

#define rep(i, a, b) for (int i = a; i < b; i++)
using ll = long long;

int main(){
	int n, m;
	cin >> n >> m;
	vector<int> a(n), b(m);
	rep(i, 0, n) cin >> a[i];
    rep(i, 0, m) cin >> b[i];
    int ans = 0;
    rep(i, 0, n) {
        int j = a[i] - 1;
        b[j]--;
        if(b[j] < 0) ans++;
    }
	cout << ans << endl;
}