#include<bits/stdc++.h>
#define rep(i, x) for(ll i = 0; i < x; i++)
#define rep2(i, x) for(ll i = 1; i <= x; i++)
#define all(a) (a).begin(),(a).end()
using ll = long long;
using ld = long double;
const ll INF = 10000000000000000;
using namespace std;
signed main() {
	ll n, sum = 0; cin >> n;
	rep(i, n) { ll a; cin >> a; sum += a; }
	ll b; cin >> b; cout << sum - b << endl;
	return 0;
}