#include <iostream>
using namespace std;

int main() {
    int n, real_ans = 0, v;
    cin >> n;
    for (int i = 0; i < n; i++) {
        int a;
        cin >> a;
        real_ans += a;
    }
    cin >> v;
    cout << real_ans - v << endl;
    return 0;
}