using System;

public class Program

{

    public static void Main()

    {

        string a, b, c, d;

        Console.Write("Enter letter: ");

        a = Console.ReadLine();

        Console.Write("Enter letter: ");

        b = Console.ReadLine();

        Console.Write("Enter letter: ");

        c = Console.ReadLine();

        Console.Write("Enter letter: ");

        d = Console.ReadLine();

        Console.WriteLine("Reverse order - {0} {1} {2} {3}", d, c, b, a);

    }

}