def solve():
    Q=int(input())

    def bit(x,i):
        return (x>>i)&1

    Ans=[]
    S=set()
    K=30; B=[0]*30

    for q in range(Q):
        mode,*value=map(int,input().split())
        if mode==1:
            x,=value
            if x in S:
                continue

            S.add(x)
            for i in range(K):
                if bit(x,i):
                    B[i]+=1

        elif mode==2:
            x,=value
            if x not in S:
                continue

            S.remove(x)
            for i in range(K):
                if bit(x,i):
                    B[i]-=1
        else:
            if S:
                ans=0
                for i in range(K):
                    if B[i]==len(S):
                        ans|=1<<i
            else:
                ans=-1
            Ans.append(ans)

    return Ans

#==================================================
import sys
input=sys.stdin.readline
write=sys.stdout.write

write("\n".join(map(str,solve())))