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