#include <iostream>
using namespace std;
using ll = long long;

ll N;
int main() {
  cin.tie(0); ios_base::sync_with_stdio(false); 
  cin >> N;
  ll ans = 0;
  for(ll i = 1; i * i <= N; ++i) {
    if(N % i == 0) {
      ans += i;
      if(N / i != i) ans += N / i;
    }
  }
  cout << ans << endl;
  return 0;
}