// Simple program to demonstrate the use of abstract classes
import java.util.*;

public class ShapeClient {
   public static void main(String[] args) {
      Shape[] shapes = { new Circle(2),
                          new Square(4.1),
                          new Rectangle(3.5, 2.3),
                          new Circle(1),
                          new Rectangle(1.8, 5),
                          new Circle(3.4),
                        };
                        
      System.out.println(Arrays.toString(shapes));
      Arrays.sort(shapes);
      System.out.println(Arrays.toString(shapes));
   }
}