public class PersonExample {
    public static void main(String[] args) {
	
	Person p0 = new Person(100);
	Person p1 = new Person(100);
	Person p2 = new Person(200);
	Person p3 = new Person(300);

	System.out.println(p0==p1);
	System.out.println(p0.equals(p1));
	System.out.println(p1.compareTo(p2));
	System.out.println(p3.compareTo(p1));

    }
}

class Person implements Comparable {
    private int weight;
    public Person(int w) { weight = w; }
    public int compareTo(Object o) {
	return weight - ((Person) o).weight;
    }
    public boolean equals(Person p) {
	return p.weight==weight;
    }   
}