#include <bits/stdc++.h>
using namespace std;
int a[100001];
int main() {
  int n;
  int cnt;
  cin >> n;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    cnt += a[i] - 1;
  }
  cout << cnt << endl;
  return 0;
}
