#include <bits/stdc++.h>
using namespace std;
int num[3001];
int main() {
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) cin >> num[i];
  int sum = 0;
  for (int i = 0; i < n; i++) sum += num[i] - 1;
  cout << sum;
  return 0;
}
