C++ :

#include <iostream>
using namespace std;
int main() {
    int n, m;
    cin >> n >> m;
    int ans = 0;
    for (int i = 1; i <= m; ++i) {
        int x;
        cin >> x;
        if (x > n) ans++;
        else n -= x;
    }
    cout << ans;
    return 0;
}