Q = int(input())

D = (1<<30) - 1
N = Q

# N: 処理する区間の長さ
N0 = 2**(N).bit_length()
data = [D]*(2*N0)

# a_k の値を x に更新
def update(k, x):
    k += N0-1
    data[k] = x
    while k >= 0:
        k = (k - 1) // 2
        data[k] = data[2*k+1] & data[2*k+2]
# 区間[l, r)のAND
def query(l, r):
    s = D
    L = l + N0; R = r + N0
    while L < R:
        if R & 1:
            R -= 1
            s &= data[R-1]
        if L & 1:
            s &= data[L-1]
            L += 1
        L >>= 1; R >>= 1
    return s

dic = {}

for i in range(Q):
    quer = list(map(int,input().split()))
    if quer[0] == 3:
        if dic:
            print(query(0,N))
        else:
            print(-1)
    else:
        t,u = quer
        if t == 1:
            if u not in dic:
                dic[u] = i
                update(i,u)
        else:
            if u in dic:
                update(dic[u],D)
                dic.pop(u)