import bisect
import copy
import decimal
import fractions
import heapq
import itertools
import math
import random
import sys
import time
from collections import Counter,deque,defaultdict
from functools import lru_cache,reduce
from heapq import heappush,heappop,heapify,heappushpop,_heappop_max,_heapify_max
def _heappush_max(heap,item):
    heap.append(item)
    heapq._siftdown_max(heap, 0, len(heap)-1)
def _heappushpop_max(heap, item):
    if heap and item < heap[0]:
        item, heap[0] = heap[0], item
        heapq._siftup_max(heap, 0)
    return item
from math import gcd as GCD
read=sys.stdin.read
readline=sys.stdin.readline
readlines=sys.stdin.readlines
write=sys.stdout.write

Q=int(readline().rstrip())
se=set()
cnt=[0]*30
for q in range(Q):
    query=tuple(map(int,readline().split()))
    if query[0]==1:
        _,x=query
        if not x in se:
            se.add(x)
            for i in range(30):
                cnt[i]+=x>>i&1
    elif query[0]==2:
        _,x=query
        if x in se:
            se.remove(x)
            for i in range(30):
                cnt[i]-=x>>i&1
    else:
        if len(se)==0:
            ans=-1
        else:
            ans=sum((cnt[i]==len(se))<<i for i in range(30))
        print(ans)