def resolve():
    q = int(input())
    s = set()
    cnt = [0] * 30
    for _ in range(q):
        query = tuple(map(int, input().split()))
        if query[0] == 1:
            x = query[1]
            if x not in s:
                s.add(x)
                i = 0
                while x:
                    if x & 1:
                        cnt[i] += 1
                    x >>= 1
                    i += 1
        elif query[0] == 2:
            x = query[1]
            if x in s:
                s.remove(x)
                i = 0
                while x:
                    if x & 1:
                        cnt[i] -= 1
                    x >>= 1
                    i += 1
        else:
            if s:
                print(sum(1 << i for i, x in enumerate(cnt) if x == len(s)))
            else:
                print(-1)
        # print(s, cnt)


if __name__ == "__main__":
    resolve()