public class HelloWorld{

     public static void main(String []args){
        System.out.println("Hello World");
        
        Product p1 = new Product(1, 50 , 9999);
        Product p2 = new Product(2 , 990);
        Product p3 = new Product(3 , 40 , 1);
        System.out.println(p1);
        System.out.println(p2.toString());
        System.out.println(p3.toString());
        p3.sell(50);
        p1.sell(50);
     }
}

class Product{
    private int ID;
    private int price;
    private int stock;
    public Product(int ID, int price, int stock)
    {
        this.ID = ID ;
        this.price = price;
        this.stock = stock;
 
    }
 
    public Product(int ID, int price)
    {
        this.ID = ID ;
        this.price = price ;
        stock = 0;
    }
 
    public String toString ()
    {
        return "This Products's ID is " + ID + ", Price is " + price + " , Stock is " + stock;
    }
    
    public void sell (int a)
    {
        if (stock >= a)
        {
            System.out.println(a * price);
        }
        else
        {
            System.out.println("Insufficient Stock");
        }
        stock = stock - a;
    }   
    
}