import heapq

q = int(input())
heap = []
deleted = set()
for _ in range(q):
    line = input().split()
    command = line[0]
    if len(line) > 1:
        val = int(line[1])
    if command == "1":
        if val in deleted:
            deleted.remove(val)
        else:
            heapq.heappush(heap, val)
    elif command == "2":
        deleted.add(val)
    elif command == "3":
        x = heap[0]
        while x in deleted:
            heapq.heappop(heap)
            deleted.remove(x)
            x = heap[0]
        print(x)