using System;
using System.Collections.Generic;
using System.Linq;

namespace Problem_04b
{
    class Program
    {
        static void Main()
        {
            //Alternate Solution
            string[] inputElements = Console.ReadLine().Split(' ').ToArray();

            for (int i = 0; i < inputElements.Length; i++)
            {
                Console.Write(inputElements[i]);
                if (i < inputElements.Length-1 && (inputElements[i] == inputElements[i+1]))
                {
                    Console.Write(" ");
                }
                else
                {
                    Console.WriteLine();
                }
            }
        }
    }
}