#include <bits/stdc++.h>
using ll = long long int;
using namespace std;
ll mod=1e9+7;
      
      
int main(){
  ll n;
  cin >>n;
  ll q=sqrt(n);
  ll ans=0;
  for(int i=1;i<=q;i++){
      if(n%i==0){ans+=(i+n/i);}
      if(n%i==0 && n/i==i){ans-=i;}
  }
  cout << ans << endl;
}