using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("What is your first name?");

        string FirstName = Console.ReadLine();

        Console.WriteLine("What is your last name?");

        string LastName = Console.ReadLine();

        //concatenation

        Console.WriteLine("Hello, " + FirstName + " " + LastName + ".");

        //placeholder syntax (preferred)

        Console.WriteLine("Hello, {0} {1}.", FirstName, LastName);

    }

}