#include <iostream>

using namespace std;

int main()
{
  int n,total_t,total_y;
  cin>>n;
  int d[n];
  for(int i=0; i<n; i++){
    cin>>d[i];
  }
  cin>>total_y;
  total_t = 0;
  for(int i=0; i<n; i++){
    total_t += d[i];
  }
  cout<<total_t-total_y<<endl;
  return 0;
}