using System;
using System.Text;

class Program
{
    static void Main()
    {
        string s = Console.ReadLine();
        StringBuilder sb = new StringBuilder();

        char prev = '\0'; // 初期値は空文字に近いもの
        foreach (char c in s)
        {
            if (c != prev)
            {
                sb.Append(c);
                prev = c;
            }
        }

        Console.WriteLine(sb.ToString());
    }
}