import sys
def input():
  return sys.stdin.readline()[:-1]
Q=int(input())
ans=[set() for _ in range(30)]
S=set()
for _ in range(Q):
  query=list(map(int,input().split()))
  if query[0]==1:
    if query[1] not in S: S.add(query[1])
    for i in range(30):
      if query[1] not in ans[i] and (query[1]>>i)&1==1: ans[i].add(query[1])
  elif query[0]==2:
    if query[1] in S: S.remove(query[1])
    for i in range(30):
      if query[1] in ans[i] and (query[1]>>i)&1==1: ans[i].remove(query[1])
  else:
    if len(S)>0: print(sum([1<<i for i in range(30) if len(ans[i])==len(S)]))
    else: print(-1)