using System;
using System.Text.RegularExpressions;
 
public class Test
{
    public static void Main()
    {   
        string msg= "{1,{Cat,{Blue,1}},2,{Dog,5}}";
        msg = msg.Substring(1, msg.Length - 2);
        string[] charSetOccurences = Regex.Split(msg, @",(?=[^{}]*(?:(?:(?'O'{)[^{}]*)+(?:(?'-O'})[^{}]*?)+)*(?(O)(?!))$)");
        foreach (string s in charSetOccurences)
        {
            Console.WriteLine(s);
        }
    }
}