#pragma GCC target("avx2")
#pragma GCC optimize("unroll-loops")

#include <algorithm>
#include <bitset>
#include <climits>
#include <cmath>
#include <cstring>
#include <deque>
#include <forward_list>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

#define ALL(x) (x).begin(), (x).end()
#define PC(x) __builtin_popcount(x)
#define PCL(x) __builtin_popcountll(x)

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
template <class T>
bool chmax(T& a, const T& b)
{
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}
template <class T>
bool chmin(T& a, const T& b)
{
    if (b < a) {
        a = b;
        return true;
    }
    return false;
}
const double PI = 3.14159265358979323846;
const double PI2 = PI * 2.0;
const double EPS = 1E-09;
const ll MOD = 1E+09 + 7; // =998244353;
const ll INFL = 1E18;
const int INFI = 1E09;
const int MAX_N = 4E+05;
struct edge {
    int to, cost, id;
};

ll di[4] = { 0, -1, 0, 1 }, dj[4] = { 1, 0, -1, 0 };

int Q, cnt;

int X[MAX_N + 1], T[MAX_N + 1], C[31];

int calc()
{
    int res = 0;
    for (int i = 0; i < 30; ++i) {
        if (C[i] == cnt) {
            res += (1 << i);
        }
    }
    return res;
}

void insert(int x)
{
    for (int i = 0; i < 30; ++i) {
        if ((x >> i) & 1) {
            C[i]++;
        }
    }
}

void erase(int x)
{
    for (int i = 0; i < 30; ++i) {
        if ((x >> i) & 1) {
            C[i]--;
        }
    }
}

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

    cin >> Q;

    for (int i = 1; i <= Q; ++i) {
        cin >> T[i];
        if (T[i] != 3) {
            cin >> X[i];
        }
    }

    set<int> st;
    for (int i = 1; i <= Q; ++i) {
        if (T[i] == 1) {
            if (st.count(X[i]) == 0) {
                insert(X[i]);
                st.insert(X[i]);
                cnt++;
            }
        } else if (T[i] == 2) {
            if (st.count(X[i]) > 0) {
                erase(X[i]);
                st.erase(X[i]);
                cnt--;
            }
        } else {
            if (cnt == 0) {
                cout << -1 << "\n";
            } else {
                cout << calc() << "\n";
            }
        }
    }

    // for (int i = 0; i < N; i++) {
    //     for (int j = 0; j < N; j++) {
    //         cout << "i = " << i << ", j = " << j << ", dp = " << dp[i][j] << "\n";
    //     }
    // }
    return 0;
}