#include <bits/stdc++.h>
using namespace std;
typedef unsigned long long ul;
typedef signed long long ll;
ul over = 1000000007;

int main(void)
{
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed;
  ll n;
  cin >> n;
  ll sum = 0;
  for (ll i = 0; i < n; ++i) {
    ll a;
    cin >> a;
    sum += a;
  }
  ll v;
  cin >> v;
  cout << sum - v << endl;
  return 0;
}