import java.util.*;
import java.io.*;
import java.math.*;

public class Main{
    /* 入出力 */
    static BufferedReader buff = new BufferedReader(new InputStreamReader(System.in));
    static StringTokenizer st;
    static PrintWriter output = new PrintWriter(System.out);
    static Scanner sc = new Scanner(System.in);
    /* 定数 */
    static final int infI = Integer.MAX_VALUE;
    static final long infL = Long.MAX_VALUE;
    static final long mod = (long)1e9+7;
    static String yes = "Yes";
    static String no = "No";
    public static final int [] y4 = {0,1,0,-1};
    public static final int [] x4 = {1,0,-1,0};
    /* グローバル変数 */

    /* Main */
    public static void main(String[] args) throws IOException{
        int Q = sc.nextInt();
        Set<Long> SET = new HashSet<>();
        int [] bit = new int[30];
        while(Q-->0) {
            int type = sc.nextInt();
            if(type == 1) {
                long x = sc.nextLong();
                if(!SET.contains(x)){
                    SET.add(x);
                    for(int i=0;i<30;i++) {
                        if(((x>>i)&1) == 1L)bit[i]++;
                    }
                }
            }
            if(type == 2) {
                long x = sc.nextLong();
                if(SET.contains(x)){
                    SET.remove(x);
                    for(int i=0;i<30;i++) {
                        if(((x>>i)&1) == 1L)bit[i]--;
                    }
                }
            }
            if(type == 3) {
                long ans = 0;
                if(SET.size() == 0) ans = -1L;
                else {
                    for(int i=0;i<30;i++) if(bit[i] == SET.size()) ans += (1<<i);
                }
                output.println(ans);
            }
        }
        output.flush();
    }
}