using static System.Math;
using System;

public class Hello
{
    static void Main()
    {
        var n = long.Parse(Console.ReadLine().Trim());
        getAns(n);
    }
    static void getAns (long n)
    {
        var imax = (int)Sqrt(n);
        var ans = 0L;
        for (int i = 1; i <= imax; i++)
        {
            if (n % i == 0)
            {
                ans += i;
                var t1 = n / i;
                if (t1 != i) ans += t1;
            }
        }
        Console.WriteLine(ans);
    }
}