#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vl = vector<long long>;

#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
#define rep(i, a, b) for (int i = (a); i < (b); i++)

mt19937 rng(random_device{}());

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);

	int q;
	cin >> q;

	unordered_set <int> S;

	rep(i, 0, q){
		int num;
		int query;

		cin >> query;

		if(query != 3) cin >> num;

		if(query == 1){
			S.insert(num);
		}
		else if(query == 2){
			S.erase(num);
		}
		else{
			if(S.empty()){
				cout << "-1\n";
				continue;
			}

			auto it = S.begin();
			int result = *it;
			it++;

			while(it != S.end()){
				result &= *it;
				it++;
			}

			cout << result << "\n";
		}
	}

	return 0;
}