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

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static string[] SList(long n) => Enumerable.Repeat(0, (int)n).Select(_ => ReadLine()).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var n = long.Parse(ReadLine());
        var ans = 0L;
        for (var i = 1L; i * i <= n; ++i)
        {
            if (n % i == 0)
            {
                ans += i;
                if (i * i < n) ans += n / i;
            }
        }
        WriteLine(ans);
    }
}