using System.Diagnostics;
using System;
using System.Linq;
using System.Numerics;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Text;
using static Functions;



static class Program
{
    static public void Main(string[] args)
    {
        Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false });
        new Solver();
        Console.Out.Flush();
    }
}

public class Solver
{
    public Solver()
    {
        Solve();
    }

    void Solve()
    {
        int q = ri;
        var s = new SortedSet<int>();
        var c = new int[30];
        for (int i = 0; i < q; i++)
        {
            int t = ri;
            if (t == 1)
            {
                int x = ri;
                if (!s.Contains(x))
                {
                    s.Add(x);
                    for (int j = 0; j < 30; j++) c[j] += (x >> j) & 1;
                }
            }
            if (t == 2)
            {
                int x = ri;
                if (s.Contains(x))
                {
                    s.Remove(x);
                    for (int j = 0; j < 30; j++) c[j] -= (x >> j) & 1;
                }
            }
            if (t == 3)
            {
                int ans = 0;
                int n = s.Count;
                if (n == 0) ans = -1;
                else
                {
                    for (int j = 0; j < 30; j++)
                        if (c[j] == n) ans |= 1 << j;
                }
                Write(ans);
            }
        }
    }




    int[] dx = { 1, 0, -1, 0 }, dy = { 0, 1, 0, -1 };
    //int[] dx = { 1, 1, 0, -1, -1, -1, 0, 1 }, dy = { 0, 1, 1, 1, 0, -1, -1, -1 };
    bool Safe(int x, int y, int h, int w) => 0 <= x && x < h && 0 <= y && y < w;
    const long INF = 1L << 60;
    int ri { get { return (int)sc.Integer(); } }
    long rl { get { return sc.Integer(); } }
    ulong rul { get { return sc.UInteger(); } }
    double rd { get { return sc.Double(); } }
    string rs { get { return sc.Scan(); } }
    string rline { get { return sc.Line(); } }
    public StreamScanner sc = new StreamScanner(Console.OpenStandardInput());

    T[] RepArray<T>(T t, int count) => Enumerable.Repeat(t, count).ToArray();
    void WriteJoin<T>(string s, IEnumerable<T> t) { Console.WriteLine(string.Join(s, t)); }
    void WriteMat<T>(T[,] a)
    {
        int sz1 = a.GetLength(0);
        int sz2 = a.GetLength(1);
        for (int i = 0; i < sz1; i++)
        {
            var s = new List<string>();
            for (int j = 0; j < sz2; j++) s.Add(a[i, j].ToString());
            WriteJoin(" ", s);
        }
    }
    void WriteMax(params long[] x) => Console.WriteLine(x.Max());
    void WriteMin(params long[] x) => Console.WriteLine(x.Min());
    void Write(object t) => Console.WriteLine(t.ToString());
    void Write(string str, object arg1) => Console.WriteLine(str, arg1);
    void Write(string str, object arg1, object arg2) => Console.WriteLine(str, arg1, arg2);
    void Write(string str, object arg1, object arg2, object arg3) => Console.WriteLine(str, arg1, arg2, arg3);
    void Write(string str, params object[] arg) => Console.WriteLine(str, arg);
    void WriteFlush(object t) { Console.WriteLine(t.ToString()); Console.Out.Flush(); }
    void WriteError(object t) { Console.Error.WriteLine(t.ToString()); }
    void YN(bool t) { Console.WriteLine(t ? "YES" : "NO"); }
    void Yn(bool t) { Console.WriteLine(t ? "Yes" : "No"); }
    void yn(bool t) { Console.WriteLine(t ? "yes" : "no"); }
}

public static class Functions
{
    public static int Popcount(ulong x)
    {
        x = x - ((x >> 1) & 0x5555555555555555UL);
        x = (x & 0x3333333333333333UL) + ((x >> 2) & 0x3333333333333333UL);
        x = (x + (x >> 4)) & 0x0f0f0f0f0f0f0f0fUL;
        x = x + (x >> 8);
        x = x + (x >> 16);
        x = x + (x >> 32);
        return (int)(x & 0x0000007fUL);
    }
    public static int Ctz(long x)
    {
        if (x == 0) return -1;
        return Popcount((ulong)((x & -x) - 1));
    }
    public static int SafeMod(int x, int m)
    {
        int r = x % m;
        return r < 0 ? r + m : r;
    }
    public static long SafeMod(long x, long m)
    {
        long r = x % m;
        return r < 0 ? r + m : r;
    }
    public static int Sign(long x) => x == 0 ? 0 : (x < 0 ? -1 : 1);
    public static int DigitSum(long n, int d = 10) { long s = 0; while (n > 0) { s += n % d; n /= d; } return (int)s; }
    public static long Floor(long a, long b) => a >= 0 ? a / b : (a + 1) / b - 1;
    public static long Ceil(long a, long b) => a > 0 ? (a - 1) / b + 1 : a / b;
    public static int Gcd(int a, int b) => b == 0 ? a : Gcd(b, a % b);
    public static long Gcd(long a, long b) => b == 0 ? a : Gcd(b, a % b);
    public static void Swap(ref int x, ref int y) { x ^= y; y ^= x; x ^= y; }
    public static void Swap(ref long x, ref long y) { x ^= y; y ^= x; x ^= y; }
    public static void Swap<T>(ref T x, ref T y) { T t = y; y = x; x = t; }
    public static T Clamp<T>(T x, T l, T r) where T : IComparable<T> => x.CompareTo(l) <= 0 ? l : (x.CompareTo(r) <= 0 ? x : r);
    public static T Clamp<T>(ref T x, T l, T r) where T : IComparable<T> => x = x.CompareTo(l) <= 0 ? l : (x.CompareTo(r) <= 0 ? x : r);
    public static void Chmin<T>(ref T x, T y) where T : IComparable<T> { if (x.CompareTo(y) > 0) x = y; }
    public static void Chmax<T>(ref T x, T y) where T : IComparable<T> { if (x.CompareTo(y) < 0) x = y; }
    public static int LowerBound<T>(in T[] arr, Func<T, int> comp, int l = -1, int r = -1)
    {
        if (arr.Length == 0) return -1;
        if (l == -1) l = 0;
        if (r == -1) r = arr.Length;
        while (l < r)
        {
            int x = (l + r) / 2;
            if (comp(arr[x]) < 0) l = x + 1;
            else r = x;
        }
        return l;
    }
    public static int LowerBound<T>(in List<T> list, Func<T, int> comp, int l = -1, int r = -1)
    {
        if (list.Count == 0) return -1;
        if (l == -1) l = 0;
        if (r == -1) r = list.Count;
        while (l < r)
        {
            int x = (l + r) / 2;
            if (comp(list[x]) < 0) l = x + 1;
            else r = x;
        }
        return l;
    }
    public static int UpperBound<T>(in List<T> list, Func<T, int> comp, int l = -1, int r = -1)
    {
        if (list.Count == 0) return 0;
        if (comp(list.Last()) < 0) return list.Count;
        if (l == -1) l = 0;
        if (r == -1) r = list.Count;
        while (l < r)
        {
            int x = (l + r) / 2;
            if (comp(list[x]) <= 0) l = x + 1;
            else r = x;
        }
        return l;
    }
}

public class StreamScanner
{
    public StreamScanner(Stream stream) { str = stream; }
    private readonly Stream str;
    private readonly byte[] buf = new byte[1024];
    private int len, ptr;
    public bool isEof = false;
    public bool IsEndOfStream { get { return isEof; } }
    private byte read()
    {
        if (isEof) throw new EndOfStreamException();
        if (ptr >= len)
        {
            ptr = 0;
            if ((len = str.Read(buf, 0, 1024)) <= 0) { isEof = true; return 0; }
        }
        return buf[ptr++];
    }
    public char Char()
    {
        byte b = 0;
        do b = read();
        while (b < 33 || 126 < b);
        return (char)b;
    }
    public string Line()
    {
        var sb = new StringBuilder();
        for (var b = Char(); b != 10 && !isEof; b = (char)read()) sb.Append(b);
        return sb.ToString();
    }
    public string Scan()
    {
        var sb = new StringBuilder();
        for (var b = Char(); b >= 33 && b <= 126; b = (char)read()) sb.Append(b);
        return sb.ToString();
    }
    public long Integer()
    {
        long ret = 0; byte b = 0; var ng = false;
        do b = read();
        while (b != '-' && (b < '0' || '9' < b));
        if (b == '-') { ng = true; b = read(); }
        for (; true; b = read())
        {
            if (b < '0' || '9' < b) return ng ? -ret : ret;
            else ret = ret * 10 + b - '0';
        }
    }
    public ulong UInteger()
    {
        ulong ret = 0; byte b = 0;
        do b = read();
        while (b < '0' || '9' < b);
        for (; true; b = read())
        {
            if (b < '0' || '9' < b) return ret;
            else ret = ret * 10 + b - '0';
        }
    }
    public double Double() { return double.Parse(Scan()); }
}