using System;

public class Program

{

    public static void Main(string[] args)

    {

        string firstName= "John";

        string lastName = "Doe";

        Console.WriteLine("Name:"+firstName+" "+lastName);

        Console.WriteLine("please enter a new firstName:");

        firstName = Console.ReadLine();

        Console.WriteLine("New_Name:"+firstName+" "+lastName);

        Console.ReadLine();

    }

}