#include <bits/stdc++.h>
using namespace std;
int main()
{
    int n;
    int s = 0;
    cin >> n;
    for (int i = 2;i<=sqrt(n);i++)
    {
        if(n % i ==0) 
        {
            if ( i != n/i)
            {
                s += i;
                s += n / i;
            }
            else
            {
                s += i;
            }

        }
    }
    cout << s;

    return 0;
}
/**************************************************************
	Problem: 1084
	User: mariooo
	Language: C++
	Result: Accepted
	Time:10 ms
	Memory:2072 kb
****************************************************************/