#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
#define REP(i, a, b) for(int i=a;i<b;++i)

int main(){
  ll N, A, v;
  cin>>N;
  ll as=0;
  REP(i,0,N){
    cin>>A;
    as+=A;
  }
  cin>>v;
  cout<<as-v<<endl;
  return 0;
}