#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < n; ++i)
using ll = long long;
using namespace std;
const int INF = 1e9;
const int MOD = INF + 7;

int main() {
    ll N, v;
    cin >> N;

    ll sum = 0;
    rep(i, N) {
        int t;
        cin >> t;
        sum += t;
    }
    cin >> v;

    cout << sum - v << endl;

    return 0;
}