using System;

public class Program

{

    public static string removeConsecutiveDuplicates(string input)

    {

        if(input.Length<=1)

            return input;

        if (input[0]==input[1])

            return removeConsecutiveDuplicates(input.Substring(1));

        else 

            return input[0]+removeConsecutiveDuplicates(input.Substring(1));

        //return input;

    }

    public static void Main()

    {

        string sr= "aaaaaabbbbbcddddddd";       

        Console.WriteLine(removeConsecutiveDuplicates(sr));

    }

}