23.exercise

using System;
using System.Text;


class Program
{
    static void Main()
    {
        string str = Console.ReadLine();
        int count = 0;
        int counts=0;
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < str.Length-1; i++)
        {
            counts++;
            if (str[i] == str[i + 1])
            {
                do
                {
                    count++;
                } while (str[i] != str[i+1]);
            }
            if (count < counts)
            {
                sb.Append(str[i]);
                count = 0;
                counts = 0;
            }

        }
        Console.Write(sb);
        Console.WriteLine(str[str.Length - 1]);

    }
}