from collections import defaultdict


def main():
    S = set()
    S_bit_digit = [0 for _ in range(30)]

    for _ in range(int(input())):
        query = input().split()
        if len(query) == 1:
            query_type = 3
        else:
            query_type, x = map(int, query)

        match query_type:
            case 1:
                if x in S:
                    continue
                S.add(x)

                digit_idx = 0
                while x > 0:
                    if x & 1:
                        S_bit_digit[digit_idx] += 1
                    x >>= 1
                    digit_idx += 1

            case 2:
                if x not in S:
                    continue
                S.remove(x)

                digit_idx = 0
                while x > 0:
                    if x & 1:
                        S_bit_digit[digit_idx] -= 1
                    x >>= 1
                    digit_idx += 1
            case 3:
                if not S:
                    print(-1)
                else:
                    print(
                        sum(2**digit_idx for digit_idx, digit_value in enumerate(S_bit_digit) if digit_value == len(S)))
            case _:
                raise ValueError


if __name__ == "__main__":
    main()