public class PriorityQueue extends List {

    public void insert (Comparable item) {
	length++;
	if (head == null || item.compareTo (head.cargo) > 0) {
	    head = new Node (item, head);
	    return;
	}
	Node node = head;
	for (; node.next != null; node = node.next) { 
	    if (item.compareTo (node.next.cargo) > 0) {
		break;
	    }
	}
	Node newNode = new Node (item, node.next);
	node.next = newNode;
    }

    public Comparable remove () {
	return (Comparable) removeFirstNode ();
    }
}