#include <bits/stdc++.h>
using namespace std;
long long n;
long long sum = 0;
void input() {
  cin >> n;
  long long x;
  for (long long i = 1; i <= n; i++) {
    cin >> x;
    sum += x - 1;
  }
  return;
}
void solve() {
  cout << sum;
  return;
}
void output() { return; }
signed main() {
  ios_base::sync_with_stdio(false);
  input();
  solve();
  output();
  return 0;
}
