#include <iostream>
#include <cmath>
#include <string>
#include <vector>
#include <map>
#include <set>
#include <list>
#include <deque>
#include <algorithm>
#include <iomanip>

#define FOR(i, a, b) for(int i = a;i < b;i++)
#define REP(i, n) for(int i = 0;i < n;i++)
#define REPR(i, n) for(int i = n;i >= 0;i--)

#define ALL(a) (a).begin(),(a).end()
#define SORT(c) sort((c).begin(),(c).end())

#define LL long long

using namespace std;

//================================================
int main() {
	int N;
	int A = 0;
	LL v, ans;

	cin >> N;

	int tmp;
	REP(i, N) {
		cin >> tmp;
		A += tmp;
	}

	cin >> v;
	ans = A - v;

	cout << ans << endl;
	return 0;
}