using System;
using System.Linq;
 
class Program
{
    static void Main()
    {
        var n = long.Parse(Console.ReadLine());
        var rootN = (int) Math.Sqrt(n);
        var ans =
            (from i in Enumerable.Range(1, rootN)
             where n % i == 0
             let arr = new []{ 0, i, n / i }
             select (from j in Enumerable.Range(1, 2)
                     where arr[j] != arr[j-1]
                     select arr[j]
                    ).Sum()
            ).Sum();
 
        Console.Write(ans);
    }
}