#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: lijinkai
	Language: C++
	Result: Accepted
	Time:11 ms
	Memory:2072 kb
****************************************************************/