#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<ll, ll>;
int main() {
  int n;
  vector<int> v(n);
  for (int i = 0; i < n; i++) cin >> v.at(i);
  int sum = 0;
  for (int i = 0; i < n; i++) {
    sum += v.at(i);
  }
  cout << sum - n << endl;
}
