SZYFR CEZARA

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace ConsoleApplication1

{

class Program

{

static void Main(string[] args)

{

var b = 'z' - 'a' + 1;

var d = new Random().Next(1, b) - 'a';

foreach (var c in Console.ReadLine())

{

if (Char.IsLower(c))

{

Console.Write(Convert.ToChar((c + d) % b + 'a'));

}

else

{

Console.Write(c);

}

}

Console.WriteLine();

Console.ReadKey(true);

}

}

}