#include <bits/stdc++.h>
using namespace std;
int n, m, ans, cnt, a[1005];
string s;
int main() {
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    ans += a[i];
    ans--;
  }
  cout << ans << endl;
  return 0;
}
