#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <set>
#include <queue>
#include <string>
#include <iomanip>
#include <map>
using namespace std;

#define ll long long int
#define ti4 tuple<int,int,int,int>
#define pii pair<ll,ll>

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