#include<bits/stdc++.h>
using namespace std;
int main()
{
	int i,n,s=0;
	cin>>n;
	for(i=2;i<=sqrt(n);i++){
		if(n%i==0){
			if(sqrt(n)!=i)
			s=s+i+n/i;
			else
			s+=sqrt(n);
		}
	}
	cout<<s;
return 0;
}
/**************************************************************
	Problem: 1084
	User: houshanglin
	Language: C++
	Result: Accepted
	Time:11 ms
	Memory:2072 kb
****************************************************************/