st = set([])
one_num = [0] * 65
zero_num = [0] * 65
for _ in [0] * int(input()):
    lis = list(map(int, input().split()))
    # print(one_num, zero_num)
    if(lis[0] == 1):
        x = lis[1]
        if(x in st):
            continue
        st.add(x)
        for i in range(65):
            bit = (x >> i) & 1
            one_num[i] += bit
            zero_num[i] += bit ^ 1
    elif(lis[0] == 2):
        x = lis[1]
        if(x not in st):
            continue
        st.discard(x)
        for i in range(65):
            bit = (x >> i) & 1
            one_num[i] -= bit
            zero_num[i] -= bit ^ 1
    else:
        ans = 0
        for i in range(65):
            ans |= (one_num[i] > 0 and zero_num[i] == 0) << i
        if not(st):
        	ans = -1
        print(ans)