using System;

public class TestClass
{
  private string MyColor = "yellow";

   public string Color
  {
     // Default Constructor
     Color()
     {
     }
     // Overloaded constructor - sets color from method call
     Color(String x)
     {
        set MyColor = x;
     }
     // Accessor - gets property of object
     get
     {
       return MyColor;
     }
     // Mutator - sets property of object
     set
     {
       MyColor = value;
     }
  }


  public static void Main()
  {
     TestClass c = new TestClass();
     Console.WriteLine(c.Color); // get
     c.Color = "blue";           // set
     Console.WriteLine(c.Color); // get
  }
}

public class Product
    {
        private int pNumber, quantity;
        private string description, unit;

        public Product()
        {
            this.pNumber = this.quantity = 0;
            this.description = "no description";
            this.unit = "no unit of measure";
        }

        public Product(int prN, int qtd, string desc, string un)
        {
            this.pNumber = prN;
            this.quantity = qtd;
            this.description = desc;
            this.unit = un;
        }

        public int _productNumber
        {
            get { return pNumber; }
            set { if (value > 0) pNumber = value; }
        }
        public int _quantity
        {
            get { return quantity; }
            set { if (value > 0) quantity = value; }
        }
        public string _description
        {
            get { return description; }
            set { if (value != null && value != "") description = value; }
        }
        public string _unit
        {
            get { return unit; }
            set { if (value != null && value != "") unit = value; }
        }
    }