#include <bits/stdc++.h>
using namespace std;
using ll = int64_t;
int main() {
  ll N;
  cin >> N;
  ll ans = 1;
  for (ll i = 0; i < N; i++) {
    ll a;
    cin >> a;
    ans += a;
  }
  cout << ans - N << endl;
  return 0;
}
