#include <iostream>

using namespace std;

int main(int argc, char *argv[])
{
  int n;
  cin >> n;
  int tmp;
  int sum = 0;
  for (int i = 0; i < n; i++) {
    cin >> tmp;
    sum += tmp;
  }

  cin >> tmp;
  cout << sum - tmp << endl;
    
  return 0;
}