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