#ifdef MY_LOCAL
#include "D://competitive_programming/debug/debug.h"
#define debug(x) cerr << "[" << #x<< "]:"<<x<<"\n"
#else
#define debug(x) 
#endif
#define REP(i, n) for(int i = 0; i < n; i ++)
#define REPL(i,m, n) for(int i = m; i < n; i ++)
#define SORT(arr) sort(arr.begin(), arr.end())
#define LSOne(S) ((S)&-(S))
#define M_PI 3.1415926535897932384
#define INF 1e18
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
typedef long long ll;
#define int ll
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> ii;
typedef vector<ii> vii;
typedef vector<vii> vvii;
typedef double ld;
typedef tree<int,null_type,less<int>, rb_tree_tag, tree_order_statistics_node_update> ost;

signed main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	int q;cin>>q;
	set<int> ss;
	vi curct(30, 0);
	REP(i, q) {
		int ty;cin>>ty;
		if (ty == 3) {
			if (ss.empty()) {
				cout<<-1<<"\n";
			} else {
				int curans = 0;
				REP(j, 30) {
					if (curct[j] == (int)ss.size()) {
						curans += (1LL<<j);
					}
 				}
 				cout<<curans<<"\n";
			}
		} else if (ty == 2) {
			int x;cin>>x;
			if (ss.find(x) == ss.end()) continue;
			ss.erase(x);
			REP(j, 30 ){
				if ((1LL<<j)&x) {
					curct[j]--;
				}
			}
		} else {
			int x;cin>>x;
			if (ss.find(x) != ss.end()) continue;
			ss.insert(x);
			REP(j, 30 ){
				if ((1LL<<j)&x) {
					curct[j]++;
				}
			}
		}
	}
}