public abstract class Shape implements Comparable<Shape> {
	private String name;
	
	public abstract double area();
	
	public Shape(String name) {
		this.name = name;
	}
	
	public String toString() {
		return name + " of area " + area();
	}
	
  	public int compareTo(Shape other) {
		if (area() == other.area()) {
			return 0;
		} else if (area() < other.area()) {
			return -1;
		} else { // area() > other.area()
			return 1;
		}
	}
}