using System;

public class Program

{

    public static void Main()

    {

        string [] lines = {"1","2","3"};

        string [] linesTwo = {"2.1","2.2","2.3"};

        var z = new string[lines.Length + linesTwo.Length];

        Array.Sort<string>(z);

               lines.CopyTo(z, 0);

                linesTwo.CopyTo(z, lines.Length);

                Array.Sort<string>(z);

        foreach(var i in z)

        {

            Console.WriteLine(i);

        }

        //Console.WriteLine("Hello World");

    }

}