using System;
using System.Collections.Generic;
using System.Linq;



public abstract class Shape : IComparable
{
    protected double s;
    public Shape(double s)
    {
        this.s = s;
    }
    public virtual double S()
    {
        return s;
    }
    public virtual int CompareTo(object o)
    {
        if (o == null) return 1;

        Shape otherShape = o as Shape;
        if (otherShape != null)
            return this.S().CompareTo(otherShape.S());
        else
            throw new Exception("Невозможно сравнить два объекта");
    }

}
public class Square : Shape
{
    double side;
    public Square(double side) : base(side)
    {
        this.side = side;
    }
    public override double S()
    {
        s = side * side;
        return s;
    }
    public override int CompareTo(object o)
    {
        if (o == null) return 1;

        Square otherShape = o as Square;
        if (otherShape != null)
            return this.S().CompareTo(otherShape.S());
        else
            throw new Exception("Невозможно сравнить два объекта");
    }

}
public class CustomShape : Shape
{
    double area;
    public CustomShape(double area) : base(area)
    {
        this.area = area;
    }
    public override double S()
    {
        return area;
    }
    public override int CompareTo(object o)
    {
        if (o == null) return 1;

        CustomShape otherShape = o as CustomShape;
        if (otherShape != null)
            return this.S().CompareTo(otherShape.S());
        else
            throw new Exception("Невозможно сравнить два объекта");
    }

}
public class Triangle : Shape
{
    double _base;
    double height;
    public Triangle(double _base, double height) : base(_base)
    {
        this._base = _base;
        this.height = height;
    }
    public override double S()
    {
        s = 0.5 * _base * height;
        return s;
    }
    public override int CompareTo(object o)
    {
        if (o == null) return 1;

        Triangle otherShape = o as Triangle;
        if (otherShape != null)
            return this.S().CompareTo(otherShape.S());
        else
            throw new Exception("Невозможно сравнить два объекта");
    }

}
public class Circle : Shape
{
    double r;
    public Circle(double r) : base(r)
    {
        this.r = r;
    }
    public override double S()
    {
        s = r * r * Math.PI;
        return s;
    }
    public override int CompareTo(object o)
    {
        if (o == null) return 1;

        Circle otherShape = o as Circle;
        if (otherShape != null)
            return this.S().CompareTo(otherShape.S());
        else
            throw new Exception("Невозможно сравнить два объекта");
    }

}
public class Rectangle : Shape
{
    double width;
    double height;
    public Rectangle(double width, double height) : base(width)
    {
        this.width = width;
        this.height = height;
    }
    public override double S()
    {
        s = height * width;
        return s;
    }
    public override int CompareTo(object o)
    {
        if (o == null) return 1;

        Rectangle otherShape = o as Rectangle;
        if (otherShape != null)
            return this.S().CompareTo(otherShape.S());
        else
            throw new Exception("Невозможно сравнить два объекта");
    }
}
//using NUnit.Framework;
//using System;
//using System.Linq;
//using System.Collections.Generic;

//[TestFixture]
//public class ShapesTests
//{
//    [Test]
//    public void ShapesAreSortableOnArea()
//    {
//        // Arrange
//        double width, height, triangleBase, side, radius, area;
//        Random random = new Random((int)DateTime.UtcNow.Ticks);

//        var expected = new List<Shape>();

//        area = 1.1234;
//        expected.Add(new CustomShape(area));

//        side = 1.1234;
//        expected.Add(new Square(side));

//        radius = 1.1234;
//        expected.Add(new Circle(radius));

//        triangleBase = 5;
//        height = 2;
//        expected.Add(new Triangle(triangleBase, height));

//        height = 3;
//        triangleBase = 4;
//        expected.Add(new Triangle(triangleBase, height));

//        width = 4;
//        expected.Add(new Rectangle(width, height));

//        area = 16.1;
//        expected.Add(new CustomShape(area));

//        var actual = expected.OrderBy(x => random.Next()).ToList();

//        // Act
//        actual.Sort();

//        // Assert
//        for (var i = 0; i < 5; i++)
//            Assert.AreEqual(expected[i], actual[i]);
//    }
//}