#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n;
  cin >> n;
  long long x[n + 5];
  long long sum = 0;
  for (long long i = 0; i < n; i++) {
    cin >> x[i];
    sum += (x[i] - 1);
  }
  cout << sum << endl;
  return 0;
}
