#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int main()
{
    long i,n,c=0;
    scanf("%d",&n);
    for(i=2;i<=sqrt(n);i++)
    {
        if(n%i==0)
        {
            if(i==n/i)
            {
                c=c-i;
            }
            c=c+i+n/i;
        }
    }
    printf("%d",c);
    return 0;
}

/**************************************************************
	Problem: 1084
	User: admin
	Language: C
	Result: Accepted
	Time:16 ms
	Memory:1144 kb
****************************************************************/