#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n;
	cin>>n;
	int a=0;
	int s=0;
	for(int i=2;i<=sqrt(n);i++)
	{
		if(n%i==0)
		{
			a+=i;
			s+=a;
			s+=n/a;
		}
	}
	cout<<s+1;	
	return 0;
}
/**************************************************************
	Problem: 1084
	User: chenkexin
	Language: C++
	Result: Wrong Answer
****************************************************************/