"""
출처:프로그래머스,
https://school.programmers.co.kr/learn/courses/30/lessons/42626
"""

# 풀이 과정
def solution(scoville, K):
    import heapq
    t = scoville
    heap = []
    result = 0

    # for문 len(t) 개수만큼이라 t.sort()로 한 후 시작한거랑 동일!
    while t:
        a = t.pop()
        heapq.heappush(heap, a)

    while heap:

        a = heapq.heappop(heap)

        if a < K:
            if len(heap) > 0:
                result += 1
                b = heapq.heappop(heap)
                count = (a + b * 2)
                heapq.heappush(heap, count)
            else:
                return -1  # 다 섞어도 k 못넘음
        else:
            break

    return result