using System;

​

​

public class Circle

{

    public double Radius { get; set; }

}

​

public class Rectangle

{

    public double Width { get; set; }

    public double Height { get; set; }

}

// Area Calculator 

public class AreaCalculator

{

    public double Area(object[] shapes)

    {

        double area = 0;

        foreach (var shape in shapes)

        {

            if (shape is Rectangle)

            {

                Rectangle rectangle = (Rectangle) shape;

                area += rectangle.Width*rectangle.Height;

            }

            else

            {

                Circle circle = (Circle)shape;

                area += circle.Radius * circle.Radius * Math.PI;

            }

        }

​

        return area;

    }

​

​

}

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

    }

}