using System;

namespace Echiquier
{
	class MainClass
	{
		public static void Main (string[] args)
		{
			Console.WriteLine ("Deplacement d'un cavalier de (i, j) vers (i', j') :");
			Console.Write ("i = ");
			int i = int.Parse(Console.ReadLine());
			Console.Write ("j = ");
			int j = int.Parse(Console.ReadLine());
			Console.Write ("i' = ");
			int ip = int.Parse(Console.ReadLine());
			Console.Write ("j' = ");
			int jp = int.Parse(Console.ReadLine());
			if (i >= 1 && i <= 8 && j >= 1 && j <= 8 && ip >= 1 && ip <= 8 && jp >= 1 && jp <= 8)
			{
				if (Math.Abs(i - ip) == 2 && Math.Abs(j - jp) == 1 ||
				    Math.Abs(i - ip) == 1 && Math.Abs(j - jp) == 2)
					Console.WriteLine("Deplacement (" + i + ", " + j + ") -> (" + ip + ", " + jp + ") " +
					                  "correct.");
				else
					Console.WriteLine("Deplacement incorrect.");
			}
			else
				Console.WriteLine("Erreur de saisie.");
		}
	}
}