#include <bits/stdc++.h>
using namespace std;

int main()
{
	int N;
	cin >> N;
	long long sum = 0;
	for( int i = 0; i < N; i++ ) {
		int A;
		cin >> A;
		sum += A;
	}
	long long v;
	cin >> v;

	long long ans = sum - v;

	cout << ans << endl;
}