using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace ConsoleApplication1

{

class Program

{

static void Main(string[] args)

{

Rectangle r = new Rectangle(10, 20);

Console.WriteLine(r.area().ToString());

Console.ReadKey();

}

class Rectangle {

public double length;

public double width;

public Rectangle(double l,double w)

{

length = l;

width = w;

}

public double area()

{

return length * width;

}

}

}

}