using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Enter item quantity");

        Item objItem = new Item();

        objItem.StockInHand = Convert.ToInt32(Console.ReadLine());

        Console.ReadLine();

    }

}

public class Item

{

    private int _stockInHand;

    public int ItemId { get; set; }

    public string Name { get; set; }

    public decimal Price { get; set; }

    public int StockInHand

    {

        get

            {

                return _stockInHand;

            }

        set

            {

             _stockInHand = value;

            if (_stockInHand < 5)

                {

                    StockChanged += Item_StockChanged;

                    OnStockChanged();

                }else{

                Console.WriteLine("Enough item in stock");

            }

            }

        }

​

    private void Item_StockChanged(object sender, EventArgs e)

    {

        Order objOrder = new Order();

        objOrder.RefillRequest();

        Console.WriteLine(StockInHand);

    }

        public event System.EventHandler StockChanged;

   protected virtual void OnStockChanged()

   {

       if (StockChanged != null) StockChanged(this, EventArgs.Empty);

   }

}

public class Order

{

    public void RefillRequest()

    {

        Console.Write("Purchase order submitted");

    }

}