using System;
using System.Collections.Generic;
using System.Linq;
using static System.Console;
using static System.Math;

class Program
{
    static void Main()
    {
        var N = long.Parse(ReadLine());
        WriteLine(yakusuu(N).Sum());
    }

    public static long[] yakusuu(long n)//O(sqrt N)
    {
        if (n < 1) return new long[0];//Assert
        var r = new List<long>();
        for (int i = 1; i * i <= n; i++)
        {
            if (n % i == 0)
            {
                r.Add(i);
                if (i * i != n) r.Add(n / i);
            }
        }
        return r.ToArray();
    }
}