#include <bits/stdc++.h>
using namespace std;
const double pi =
    3.141592653589793238462643383279502884197169399375105820974944592307816406286208998628034825342;
const int mod = 1000000007;
int main() {
  int n, a[3333] = {};
  long long ans = 0LL;
  cin >> n;
  for (int i = (0); i < (n); ++i) {
    int t;
    cin >> t;
    ans += t;
  }
  cout << ans - n << endl;
  return 0;
}
