#include <bits/stdc++.h>
int main() {
  long long a = 0, b = 0, c = 0, hairetu[1000] = {}, mi = 0, ma = 0, ansa = 0,
            ansb = 0, count = 1;
  using namespace std;
  int x = 0, y = 0, z = 0;
  std::string str, strt, str_s;
  bool okada = false;
  cin >> x;
  for (int i = 0; i < x; i++) {
    std::cin >> hairetu[i];
    a += hairetu[i] - 1;
  }
  cout << a << endl;
}
