import collections
CA = collections.Counter()
S = set()
for _ in range(int(input())):
    Q = list(map(int, input().split()))
    if Q[0]==1:
        x = Q[1]
        if not x in S:
            S.add(x)
            bx = format(x, 'b').zfill(30)[::-1]
            for i,v in enumerate(bx):
                if v=='1':
                    CA[i]+=1
    if Q[0]==2:
        x = Q[1]
        if x in S:
            S.discard(x)
            bx = format(x, 'b').zfill(30)[::-1]
            for i,v in enumerate(bx):
                if v=='1':
                    CA[i]-=1
    if Q[0]==3:
        if len(S)==0:
            print(-1)
        else:
            ans = 0
            for i,v in CA.items():
                if v == len(S):
                    ans+=2**i
            print(ans)