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