#include<bits/stdc++.h>
using namespace std;
using long long ll;
const int INF = 1e8;
int main() {
	int N;
	int A;
	cin >> N;
	int sum = 0;
	for (int i = 0; i < N; i++) {
		cin >> A;
		sum += A - 1;
	}
	cout << sum << endl;
	return 0;
}