#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define rep(i, n) for (int i = 0; i < (n); i++)
#define P pair<int, int>
#define LP pair<ll, ll>


int main() {
  ll n;
  cin >> n;

  ll ans = 0;
  for (ll i = 1; i*i <= n; i++) {
    if (n%i==0) {
      if (i*i != n) ans += i +(n/i);
      else ans += i;
    }
  }
  cout << ans << endl;

  return 0;
}