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

int main() {
  int64_t n, s = 0, v;
  cin >> n;
  for (int i = 0; i < n; i++) {
    int a;
    cin >> a;
    s += a;
  }
  cin >> v;
  cout << (s - v) << endl;
  return 0;
}