#include <bits/stdc++.h>
#define ll long long int

using namespace std;

int main()
{
  ll i, n, n, x, ans = 0;
  cin >> n;
  
  for(i=0; i<n; i++)
  {
    cin >> x;
    ans += x-1;
  }
  
  cout << ans << endl;
}
