Q = int(input())

se = set()
res = 1<<30
cnt = [0]*31
for _ in range(Q):
    qu = list(map(int,input().split()))
    
    if qu[0] == 1:
        k = qu[1]
        if k not in se:
            se.add(k)
            res &= k
            b = format(k,"b")
            for i in range(len(b)):
                if b[~i] == "1":
                    cnt[i] += 1
                    
    elif qu[0] == 2:
        k = qu[1]
        if k in se:
            se.remove(k)
            b = format(k,"b")
            for i in range(len(b)):
                if b[~i] == "1":
                    cnt[i] -= 1
            res = 0
            for j in range(31):
                if cnt[j] == len(se):
                    res += pow(2,j)
                    
    else:
        if len(se) == 0: print(-1)
        else: print(res)