import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.StringTokenizer;
import java.util.TreeMap;

public class SettingExam {


    static class FloorPair {
        int queryIdx;
        int val;

        public FloorPair(int queryIdx, int val) {
            this.queryIdx = queryIdx;
            this.val = val;
        }
    }

    public static void main(String[] args) throws IOException {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int y = 0;

        int[][] queries = new int[n][2]; // first idx for type, 2nd idx for val/res
        // 0 -> add, 1 -> remove, -1 -> floor

        TreeMap<Integer, Integer> freqs = new TreeMap<>();
        ArrayList<FloorPair>[] floors = new ArrayList[n + 1];

        for (int i = 0; i < queries.length; i++) {
            queries[i][0] = -1;
            queries[i][1] = -1;
        }

        for (int i = 0; i < floors.length; i++) {
            floors[i] = new ArrayList<>();
        }

        for (int i = 0; i < n; i++) {
            String type = sc.next();
            switch (type) {
                case "floor":
                    floors[sc.nextInt()].add(new FloorPair(i, sc.nextInt()));
                    break;
                case "add":
                    queries[i][0] = 0;
                    queries[i][1] = sc.nextInt();
                    break;
                case "remove":
                    queries[i][0] = 1;
                    queries[i][1] = sc.nextInt();
                    break;
            }
        }

        int ver = 0;
        for (int i = 0; i < queries.length; i++) {
            int type = queries[i][0];
            int val = queries[i][1];
            switch (type) {
                case 0: // add
                    freqs.put(val ^ y, freqs.getOrDefault(val, 0) + 1);
                    ver++;
                    break;
                case 1: // remove
                    int prev = freqs.getOrDefault(val, -1);
                    if (prev != -1) {
                        if (prev == 1)
                            freqs.remove(val);
                        else
                            freqs.put(val, prev - 1);
                    }
                    ver++;
                    break;
                default: // floor
                    y = Math.max(0, val);
                    if (val <= -1) {
                        System.out.println("No Questions");
                    } else {
                        System.out.println(val);
                    }
                    break;
            }

            for (FloorPair p : floors[ver]) {
                Integer f = freqs.floorKey(p.val);
                if (f != null) {
                    queries[p.queryIdx][1] = f;
                }
            }
        }

    }

    static class Scanner {
        StringTokenizer st;
        BufferedReader br;

        public Scanner(InputStream s) {
            br = new BufferedReader(new InputStreamReader(s));
        }

        public String next() throws IOException {
            while (st == null || !st.hasMoreTokens())
                st = new StringTokenizer(br.readLine());
            return st.nextToken();
        }

        public int nextInt() throws IOException {
            return Integer.parseInt(next());
        }

        public long nextLong() throws IOException {
            return Long.parseLong(next());
        }

        public String nextLine() throws IOException {
            return br.readLine();
        }

        public double nextDouble() throws IOException {
            String x = next();
            StringBuilder sb = new StringBuilder("0");
            double res = 0, f = 1;
            boolean dec = false, neg = false;
            int start = 0;
            if (x.charAt(0) == '-') {
                neg = true;
                start++;
            }
            for (int i = start; i < x.length(); i++)
                if (x.charAt(i) == '.') {
                    res = Long.parseLong(sb.toString());
                    sb = new StringBuilder("0");
                    dec = true;
                } else {
                    sb.append(x.charAt(i));
                    if (dec)
                        f *= 10;
                }
            res += Long.parseLong(sb.toString()) / f;
            return res * (neg ? -1 : 1);
        }

        public boolean ready() throws IOException {
            return br.ready();
        }
    }
}