https://www.acmicpc.net/problem/1927
시간 제한 : 1초
메모리 제한 : 128MB
import heapq
n = int(input())
heap = []
result = []
for _ in range(n):
data = int(input())
if data == 0:
if heap:
result.append(heapq.heappop(heap))
else:
result.append(0)
else:
heapq.heappush(heap, data)
for data in result:
print(data)