// the pre-Java 5.0 way: interfaces specify Objects, cast to the right type

class Pair implements Comparable {
    Double x, y;
    
    public Pair(double x, double y) {
        this.x = new Double(x);
        this.y = new Double(y);
    }

    public int compareTo(Object other) {
        Pair otherp = (Pair) other;
        if ( this.x.equals(otherp.x) ) {
            return this.y.compareTo(otherp.y);
        } else {
            return this.x.compareTo(otherp.x);
        }
    }
}