https://www.acmicpc.net/problem/11279
import sys
import heapq
n=int(input())
nums=[]
for i in range(n):
x=int(sys.stdin.readline())
if x==0:
if len(nums)==0:
print(0)
else:
print(heapq.heappop(nums)[1])
else:
heapq.heappush(nums, (-x,x))
heapq.heappush(nums, (-x,x))
print(heapq.heappop(nums)[1])