using System;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        var input = "MyFavouriteChocIsDARKChocalate";

        var output = Regex.Replace(input, "(((?<!^)[A-Z](?=[a-z]))|((?<=[a-z])[A-Z]))", " $1");

        Console.WriteLine(output);

    }

}