#pragma GCC target("avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

#include <bits/stdc++.h>
using namespace std;

#define rep(i,n) for(int i = 0; i < (int)n; i++)
#define FOR(n) for(int i = 0; i < (int)n; i++)
#define repi(i,a,b) for(int i = (int)a; i < (int)b; i++)
#define pb push_back
#define all(x) x.begin(),x.end()
//#define mp make_pair
#define vi vector<int>
#define vvi vector<vi>
#define vll vector<ll>
#define vvll vector<vll>
#define vs vector<string>
#define vvs vector<vs>
#define vc vector<char>
#define vvc vector<vc>
#define pii pair<int,int>
#define pllll pair<ll,ll>
#define vpii vector<pair<int,int>>
#define vpllll vector<pair<ll,ll>>
#define vpis vector<pair<int,string>>
#define vplls vector<pair<ll, string>>
#define vpsi vector<pair<string, int>>
#define vpsll vector<pair<string, ll>>

template<typename T>
void chmax(T &a, const T &b) {a = (a > b? a : b);}
template<typename T>
void chmin(T &a, const T &b) {a = (a < b? a : b);}

using ll = long long;
using ld = long double;
using ull = unsigned long long;

const ll INF = numeric_limits<long long>::max() / 2;
const ld pi = 3.1415926535897932384626433832795028;
const ll mod = 998244353;
int dx[] = {-1, 0, 1, 0, -1, -1, 1, 1};
int dy[] = {0, -1, 0, 1, -1, 1, -1, 1};

#define int long long

void solve() {
    int q;
    cin >> q;
    const int BIT = 31;
    vector<int> bit(BIT, 0);
    set<int> st;
    while(q--) {
        int t;
        cin >> t;
        
        if(t == 1) {
            int x;
            cin >> x;
            if(st.find(x) == st.end()) {
                st.insert(x);
                rep(i, BIT) {
                    if(x>>i & 1) {
                        bit[i]++;
                    }
                }
            }
        }else if(t == 2) {
            int x;
            cin >> x;
            if(st.find(x) != st.end()) {
                st.erase(x);
                rep(i, BIT) {
                    if(x>>i & 1) {
                        bit[i]--;
                    }
                }
            }
        }else {
            int ans = 0;
            rep(i, BIT) {
                if(bit[i] == st.size()) ans += (1<<i);
            }
            if(st.size() == 0) cout << -1 << endl;
            else cout << ans << endl;
        }
    }   
}

signed main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    solve();
    return 0;
}