//Inheritance  and constructor in C#
class a
{
	public a()
	{
		System.Console.WriteLine("constr a");	
	}
	public virtual void display()
	{
		System.Console.WriteLine("A");
	}
}
class b : a //b is child of a
{
	public b()
	{
		System.Console.WriteLine("constr b");	
	}
	public override void display()
	{
		System.Console.WriteLine("B");
	}
}
class d : b //d is child of b
{
	public d()
	{
		System.Console.WriteLine("constr d");	
	}
	public override  void display()
	{
		System.Console.WriteLine("D");
	}
}

class c 
{
	public static void Main()
	{
		d x=new d();//Normally object of child
		x.display();
	}
}

/*
	constr calling:- top to bottom
	method :- bottom to top
*/