using System;

using System.Linq;

using System.Collections;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var chars = new char[] { 'А', 'Н', 'О', 'Р', 'С' };

​

        var counter = 0;

        var toCompare = "ААА";

        while (true)

        {           

            counter++;

            if (toCompare == "ССС")

            {

                break;

            }

            if (toCompare[2] != 'С')

            {

                var charIndex = Array.IndexOf(chars, toCompare[2]) + 1;

                toCompare = toCompare[0].ToString() + toCompare[1] + chars[charIndex];

                Console.WriteLine(counter + ": " + toCompare + ".");

                continue;

            }

            if (toCompare[1] != 'С')

            {

                var charIndex = Array.IndexOf(chars, toCompare[1]) + 1;

                toCompare = toCompare[0].ToString() + chars[charIndex] + toCompare[2];

                Console.WriteLine(counter + ": " + toCompare + ".");

                continue;

            }

            if (toCompare[0] != 'С')

            {

                var charIndex = Array.IndexOf(chars, toCompare[0]) + 1;

                toCompare = chars[charIndex].ToString() + "АА";

                Console.WriteLine(counter + ": " + toCompare + ".");

                continue;

            }

        }

        Console.WriteLine("Finish.");

    }

}