using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Enter Item quantity \n");

       Item item = new Item();

       var value = Console.ReadLine();

       if (!string.IsNullOrEmpty(value))

       {

          item.StockInHand -= Convert.ToInt32(value);

          Console.WriteLine("Remaining Stock-InHand :" + Math.Max(0, item.StockInHand));

        }

    }

}

public class Item

{

    private int _stockInHand;

​

    public Item()

    {

        StockInHand = 10;

    }

    public int ItemId { get; set; }

    public string Name { get; set; }

    public decimal Price { get; set; }

    public int StockInHand

    {

        get

            {

                return _stockInHand;

            }

        set

            {

             _stockInHand = value;

            // check if stockInHand is out of stock

            if (_stockInHand < 1)

            {

                Console.WriteLine("Out-of-Stock!. Cannot take orders");

            }

            // check if stockInHand reduced lesser than 5

            else if (_stockInHand < 5)

            {

                StockChanged += Item_StockChanged;

                OnStockChanged();

             }

   }

}

​

    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");

    }

}