using System;

namespace PermutationQuatreOctets
{
	class MainClass
	{
		public static void Main (string[] args)
		{
			Console.WriteLine ("Saisissez une valeur : ");
			int v = int.Parse(Console.ReadLine());			
			Console.WriteLine ("Vous avez saisi " + v + ".");
			int d = v & 255;
			v >>= 8;
			int c = v & 255;
			v >>= 8;
			int b = v & 255;
			v >>= 8;
			int a = v;
			Console.WriteLine("Les quatre octets donnent les valeurs " +
			                  a + ", " + b + ", " + c + " et " + d + ".");
			v = d;
			v <<= 8;
			v |= c;
			v <<= 8;
			v |= b;
			v <<= 8;
			v |= a;
			Console.WriteLine("Après permutation on obtient " + v + ".");
			d = v & 255;
			v >>= 8;
			c = v & 255;
			v >>= 8;
			b = v & 255;
			v >>= 8;
			a = v;
			Console.WriteLine("Ce qui correspond aux octets " +
			                  a + ", " + b + ", " + c + " et " + d + ".");
			v = d;
			v <<= 8;
			v |= c;
			v <<= 8;
			v |= b;
			v <<= 8;
			v |= a;
			Console.WriteLine("En effectuant la permutation inverse, on retrouve bien " 
			                  + v + ".");						
		}
	}
}