import sys

# sys.setrecursionlimit(1000005)
int1 = lambda x: int(x)-1
pDB = lambda *x: print(*x, end="\n", file=sys.stderr)
p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr)
def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def SI(): return sys.stdin.readline().rstrip()

# dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
inf = (1 << 63)-1
# inf = (1 << 31)-1
md = 10**9+7
# md = 998244353

q = II()
s = set()
cnt = [0]*30
a = (1 << 30)-1

for _ in range(q):
    t, *xx = LI()
    if t == 1:
        x = xx[0]
        if x not in s:
            for i in range(30): cnt[i] += x >> i & 1
            s.add(x)
    if t == 2:
        x = xx[0]
        if x in s:
            for i in range(30): cnt[i] -= x >> i & 1
            s.discard(x)
    if t == 3:
        if s:
            ans = 0
            for i in range(30):
                if cnt[i] == len(s):
                    ans |= 1 << i
            print(ans)
        else:
            print(-1)