import java.util.*;

class Main {
    private static final Set<Point> unitCircle;
    static {
        unitCircle = new HashSet<Point>();
        unitCircle.add(new Point(1, 0));
        unitCircle.add(new Point(0, 1));
        unitCircle.add(new Point(-1, 0));
        unitCircle.add(new Point(0, -1));
    }
    public static boolean onUnitCircle(Point p) {
        return unitCircle.contains(p);
    }
    public static void main(String... args) {
      Point p = new Point(1, 0);
      System.out.println(p.toString() + " is on unitCircle? " + onUnitCircle(p));
      p = new ColorPoint(1, 0, 1);
      System.out.println(p.toString() + " is on unitCircle? " + onUnitCircle(p));
    }
}