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