using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        Product p= Product.GetProduct();

        Console.WriteLine(p.WelcomeMessage);

    }

}

​

public class Product

{

    public string Name { get;set; }

    public bool InStock {get;} = true;

    private string _welcomeMessage = null;

    public string WelcomeMessage 

    {

        get => _welcomeMessage ?? $"{Name} says Hi"; 

        private set => _welcomeMessage = value;

    }

    public Product(bool stock = false)

    {

        InStock = stock;

        WelcomeMessage ="g";

    }

    public static Product GetProduct()

    {

        return new Product(){Name = "Jacket"};

    }

}

​