#include <bits/stdc++.h>

using namespace std;

#define REP(i, n) for(int i = 0; i < n; i++)

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    int n;
    cin >> n;
    int truesum = 0, t;
    REP(i, n) {
        cin >> t;
        truesum += t;
    }
    int yuki;
    cin >> yuki;
    cout << truesum - yuki << endl;
    return 0;
}