#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;
}
/**************************************************************
	Problem: 1084
	User: fuyijun
	Language: C++
	Result: Accepted
	Time:12 ms
	Memory:2072 kb
****************************************************************/