#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
  int n;
  cin >> n;
  vector<int> V(n);
  for (int i = 0; i < n; i++) cin >> V[i];
  int sum;
  for (int i = 0; i < n; i++) {
    sum += V[i] - 1;
  }
  cout << sum << endl;
}
