if (A == null || A.isEmpty()) {
            return -1;
        }
        int count = 0;
        PriorityQueue<Integer> pq = new PriorityQueue<>(A);
        while (0 < pq.size()) {
            if (k <= pq.peek()) {
                return count;
            }
            if (pq.size() == 1) {
                return -1;
            }
            pq.offer(pq.poll() + 2 * pq.poll());
            count++;            
        }

        return -1;
    }