#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

#define RREP(i,s,e) for (i = s; i >= e; i--)
#define rrep(i,n) RREP(i,(int)(n)-1,0)
#define REP(i,s,e) for (i = s; i <= e; i++)
#define rep(i,n) REP(i,0,(int)(n)-1)
#define INF 100000000

typedef long long ll;

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