#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef pair<int,int> P;
 
const int INF = 1e9;
const int mod = 1e9+7;
const double EPS = 1e-10;
const double PI = acos(-1.0);

int main()
{
    ll n,sum = 0,v;
    cin >> n;
    for(int i = 0; i < n; i++){
        int a; cin >> a;
        sum += a;
    }
    cin >> v;
    cout << sum - v << endl;
    return 0;
}