def cookies(k: int, A: list) -> int:
    heapq.heapify(A)
    counter = 0         # no. of operations
    while A[0] < k:     # smallest element always first
        if len(A) < 2:
            return -1
        first = heapq.heappop(A) 
        second = heapq.heappop(A) 
        heapq.heappush(A, first + 2 * second)
        counter += 1
    return counter