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

signed main(){
  int N;
  cin >> N;
  int ans = 0;
  for( int i = 0; i < N; i++ ){
    int A;
    cin >> A;
    ans += A;
  }
  int V;
  cin >> V;
  cout << ans-V << endl;
}