using System;

public class Program

{

    public static void Main()

    {string s= Console.ReadLine();

     string result= string.Empty;

     int a =s.Length;

     for( var i=0;i<a;i++)

     {

         if(i%2==0)

             result=result+s[i];

     }

        Console.WriteLine(result);

    }

}