interface MyComparable {
	public int compareTo(Object o);
}

// Must use java.lang.Comparable in order for this to work with Arrays.sort.
class Rectangle implements Comparable {
	private int length;
	private int width;
	
	public Rectangle(int length, int width) {
		this.width = width;
		this.length = length;
	}

	public int compareTo(Object o) {
		Rectangle r2 = (Rectangle)o;
		int r2Area = r2.length * r2.width;
		int myArea = length * width;

		if (myArea > r2Area) {
			return 1;
		} else if (myArea < r2Area) {
			return -1;
		} else {
			return 0;
		}
	}

	public String toString() {
		return "Rectangle with length: " + length + " and width: " + width;
	}
}

public class ComparableDriver {
	public static void main(String[] args) {
		Rectangle r1 = new Rectangle(5, 6);
		Rectangle r2 = new Rectangle(3, 4);
		Rectangle r3 = new Rectangle(6, 5);
		Rectangle r4 = new Rectangle(1, 2);		

		System.out.println("Rectangle r1 compared to r2: " + r1.compareTo(r2));
		System.out.println("Rectangle r1 compared to r3: " + r1.compareTo(r3));

		Rectangle[] rectArray = new Rectangle[] {r1, r2, r3, r4};
		java.util.Arrays.sort(rectArray);
		for (int i = 0; i < rectArray.length; i++) {
			System.out.println(rectArray[i]);
		}
	}
}