#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

int main() {
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
    int n, x;
    cin >> n >> x;
    rep(i, n) {
        int a;
        cin >> a;
        x -= a;
    }
    cout << -min(x, 0) << endl;
    return 0;
}