using System;

public class Program

{

    public static void Main()

    {

      char[] alphabet = new char[] {'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'}; //clear

      Console.WriteLine("Type a message that you want to encrypt: "); // clear

      string message = Console.ReadLine(); // clear

      char[] secretMessage = message.ToCharArray();  // copy signs to char type

      char[] encryptedMessage = new char[secretMessage.Length]; // new one dimensional array initialization, new array lenght = message lenght

        for(int i = 0; i < secretMessage.Length; i++)

        {

            char secretItem = secretMessage[i];                      // write in memory every char in secretMessage

            int index = Array.IndexOf(alphabet, secretItem);         // looking for char secretItem in alphabet and outcome index

            int letterPosition = (index +=3) % 26;                   // adding 3 to index and dividing it thru 26                 

            int encryptedCharacter = (alphabet[letterPosition])-97;  //  in ASCII table a letter = 97

            encryptedMessage[i] = alphabet[encryptedCharacter];

        }   

        string superSecretMessage = String.Join("",encryptedMessage);

        Console.Write(superSecretMessage);

    }

}