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

int main() {
    int n, sum = 0, k;
    cin >> n;
    for (int i = 0; i < n; i++) {
        int e;
        cin >> e;
        sum += e;
    }
    cin >> k;
    
    cout << sum - k << '\n';
    return 0;
}