#include <bits/stdc++.h>
using namespace std;
int main() {
  int N;
  int a[N];
  cin >> N;
  int i;
  for (i = 0; i <= N - 1; i++) cin >> a[i];
  int sum = 0;
  for (i = 0; i <= N - 1; i++) sum = sum + a[i];
  sum -= N;
  cout << sum << endl;
}
