#include <bits/stdc++.h>
using namespace std;
int a[3003];
int main() {
  int n, ans = 0;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    ans += a[i] - 1;
  }
  cout << ans;
  return 0;
}
