#include <algorithm>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <string>
#include <vector>
using namespace std;
typedef long long int ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;

#define rep(i,x) for(int i=0;i<(int)(x);++i)
#define reps(i,x) for(int i=1;i<=(int)(x);++i)
#define rrep(i,x) for(int i=((int)(x)-1);i>=0;i--)
#define pb push_back

int n, a, v, sum = 0;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    cin >> n;
    rep(i,n) {
        cin >> a;
        sum += a;
    }
    cin >> v;
    cout << sum - v << "\n";
    return 0;
}