#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;

int main() {
  int n;
  cin >> n;
  vector<int> a(n);
  for (auto &x : a) cin >> x;
  cout << accumulate(begin(a), end(a), 0LL) - a.size() << endl;
  return 0;
}
