if (first == null || first.key.compareTo(key) >= 0) {
        	Node answer = new Node (key, val, first);
            first = answer;
            return;
        } else {
        Node answer = new Node (key, val, null);
        Node temp = first;

        while (temp.next != null && temp.next.key.compareTo(key) < 0)
        	temp = temp.next;

        answer.next = temp.next;
        temp.next = answer;
        }