#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n;
    int cnt = 0;
    cin>>n;
    for(int i=2;i<=sqrt(n);i++)
    {
        if(n%i==0)
        {
            if(i != n/i)
            {
                cnt+=i;
                cnt+=n/i;
            }
            else
            {
                cnt+=i;
            }
        }
    }
    cout<<cnt;
    return 0;
}
/**************************************************************
	Problem: 1084
	User: wuyichen
	Language: C++
	Result: Accepted
	Time:10 ms
	Memory:2072 kb
****************************************************************/