#include <iostream>
#include <vector>

using namespace std;

int main(int argc, const char* argv[])
{
	int N;
	cin >> N;
	long long int sum;
	for (auto&& a : vector<long long int>(N)) {
		cin >> a;
		sum += a;
	}
	long long int v;
	cin >> v;
	cout << sum - v << endl;
	return 0;
}