#include <bits/stdc++.h>
#include <vector>

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>;

#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);

	vector<ll> v(100001, 0);

	ll q;
	cin >> q;

	for(ll i = 0; i < q; i++){
		ll op, num;
		cin >> op;
		if(op == 1){
			cin >> num;
			v[num] = 1;
		}else if(op == 2){
			cin >> num;
			v[num] = 0;
		}else if(op == 3){
			ll index = 0;
			while(index <= 100001 && v[index] == 0) index++;
			if(index < 100001){
				ll bitwiseResult = index;
				for(ll j = index + 1; j <= 100001; j++){
					if(v[j] == 1){
						bitwiseResult = bitwiseResult & j;
					}
				}
				cout << bitwiseResult << endl;
			}else{
				cout << -1 << endl;
			}
		}
	}

	return 0;
}