#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int a, b, c, d, i, e;
  e = 0;
  cin >> a;
  for (i = 1; i <= a; i++) {
    cin >> b;
    b = b - 1;
    e += b;
  }
  cout << e << endl;
}
