using System;

namespace ConsoleApplication
{
    class Program
    {
        //абвгдеёжзийклмнопрстуфхцчшщъыьэюя

        static string secretWord=string.Empty;
        static string cryptWord=string.Empty;

        static int [] secretInt;

        static bool exit = false;

        static void Main ( string [] args )
        {
            Console.WriteLine ( "Для шифровки сообщения нажмите клавишу \"C\"" );
            Console.WriteLine ( "Для шифровки сообщения нажмите клавишу \"E\"" );
            Console.WriteLine ( "Для шифровки сообщения нажмите клавишу \"Esc\"" );
            while (!exit )
            {
                Menu ();
            }
        }

        public static char TranslateChar ( char currentSymbol, int translation, char minSymbol = 'а', char maxSymbol = 'я' )
        {
            translation = (translation - minSymbol);
            if ( currentSymbol >= minSymbol & currentSymbol <= maxSymbol )
            {
                currentSymbol = Convert.ToChar ( currentSymbol + translation );
                if ( currentSymbol < minSymbol )
                {
                    currentSymbol = Convert.ToChar ( maxSymbol - ( minSymbol - currentSymbol - 1 ) );
                }
                else if ( currentSymbol > maxSymbol )
                {
                    currentSymbol = Convert.ToChar( minSymbol + ( currentSymbol - maxSymbol - 1 ) );
                }
                return Convert.ToChar ( currentSymbol );
            }
            return currentSymbol;
        }

        static char Crypt ( char crypt, int shift )
        {
            return   TranslateChar ( crypt, shift );
        }

        static int [] CryptWord ( string word )
        {
            char [] symbols = word.ToCharArray ();
            int [] secretInt = new int [word.Length];

            for ( int i = 0 ; i < word.Length ; i++ )
            {
                secretInt [i] = Convert.ToInt32 ( symbols [i] );
            }
            return secretInt;
        }

        static string Crypting ( string stringForCrypting, string cryptingWord )
        {
            secretWord = stringForCrypting;
            cryptWord = cryptingWord;

            secretInt = CryptWord( cryptWord );

            int step;

            string cryptedString = "";

            for ( int i = 0 ; i < secretWord.Length ; i++ )
            {
                if ( i < cryptWord.Length )
                {
                    step = secretInt [i];
                    cryptedString += Crypt ( secretWord[i], step );
                }
                else
                {
                    int ind = ( cryptingWord.Length - ( i % cryptingWord.Length ) )-1;
                    step = secretInt [ind];
                    cryptedString += Crypt ( secretWord[i], step );
                }
            }
            return cryptedString;
        }

        static string Encrypting ( string encryptingWord )
        {
            if ( encryptingWord == cryptWord )
            {
                return secretWord;
            }
            else
            {
                return "Неверное слово: ";
            }
        }

        static void Menu ()
        {

            ConsoleKeyInfo key = Console.ReadKey (true);

            switch ( key.Key )
            {
                case ConsoleKey.C:
                    Console.Write ( "Введите слово для шифровки и слово которым будет произведена шифровка: " );
                    Console.WriteLine ( Crypting ( Console.ReadLine (), Console.ReadLine () ) );
                    break;
                case ConsoleKey.E:
                    Console.Write ( "Введите секретное слово: " );
                    Console.WriteLine ( Encrypting ( Console.ReadLine () ) );
                    break;
                case ConsoleKey.Escape:
                    exit = true;
                    break;
            }
        }
    }
}