Q = int(input().strip())
S = set()
for _ in range(Q):
    query = list(map(int, input().strip().split()))
    if query[0] == 1:
        S.add(query[1])
    elif query[0] == 2:
        S.discard(query[1])
    elif query[0] == 3:
        if len(S) == 0:
            print(-1)
        else:
            result = list(S)[0]
            for num in list(S)[1:]:
                result &= num
            print(result)