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