Author has gone out of the stories about Vasiliy, so here is just a formal task description.

You are given q queries and a multiset A, initially containing only integer 0. There are three types of queries:

  1. "+ x" — add integer x to multiset A.
  2. "- x" — erase one occurrence of integer x from multiset A. It's guaranteed that at least one x is present in the multiset A before this query.
  3. "? x" — you are given integer x and need to compute the value <image>, i.e. the maximum value of bitwise exclusive OR (also know as XOR) of integer x and some integer y from the multiset A.



Multiset is a set, where equal elements are allowed.

Input

The first line of the input contains a single integer q (1 ≤ q ≤ 200 000) — the number of queries Vasiliy has to perform.

Each of the following q lines of the input contains one of three characters '+', '-' or '?' and an integer xi (1 ≤ xi ≤ 109). It's guaranteed that there is at least one query of the third type.

Note, that the integer 0 will always be present in the set A.

Output

For each query of the type '?' print one integer — the maximum value of bitwise exclusive OR (XOR) of integer xi and some integer from the multiset A.

Example

Input

10
+ 8
+ 9
+ 11
+ 6
+ 1
? 3
- 8
? 3
? 8
? 11


Output

11
10
14
13

Note

After first five operations multiset A contains integers 0, 8, 9, 11, 6 and 1.

The answer for the sixth query is integer <image> — maximum among integers <image>, <image>, <image>, <image> and <image>.
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.io.OutputStream;
import java.util.StringTokenizer;
import java.io.Writer;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author whhone
 */
public class Main {
  public static void main(String[] args) {
    InputStream inputStream = System.in;
    OutputStream outputStream = System.out;
    InputReader in = new InputReader(inputStream);
    OutputWriter out = new OutputWriter(outputStream);
    TaskD solver = new TaskD();
    solver.solve(1, in, out);
    out.close();
  }

  static class TaskD {
    public void solve(int testNumber, InputReader in, OutputWriter out) {
      MaxXorTree mxt = new MaxXorTree(30);
      mxt.insert(0);

      int T = in.nextInt();
      for (int i = 0; i < T; i++) {
        String s = in.next();
        int k = in.nextInt();

        if (s.charAt(0) == '?') {
          out.println(mxt.query(k) ^ k);
        } else if (s.charAt(0) == '+') {
          mxt.insert(k);
        } else if (s.charAt(0) == '-') {
          mxt.remove(k);
        }
      }
    }

  }

  static class InputReader {
    public BufferedReader reader;
    public StringTokenizer tokenizer;
    public String cache;

    public InputReader(InputStream stream) {
      reader = new BufferedReader(new InputStreamReader(stream), 32768);
      tokenizer = null;
      cache = null;
    }

    private String nextNoCache() {
      while (tokenizer == null || !tokenizer.hasMoreTokens()) {
        tokenizer = new StringTokenizer(nextLine());
      }
      return tokenizer.nextToken();
    }

    public String nextLine() {
      try {
        return reader.readLine();
      } catch (IOException e) {
        throw new RuntimeException(e);
      }
    }

    public String next() {
      if (cache != null) {
        String next = cache;
        cache = null;
        return next;
      } else {
        return nextNoCache();
      }
    }

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

  }

  static class OutputWriter extends PrintWriter {
    public OutputWriter(OutputStream stream) {
      super(stream);
    }

    public OutputWriter(Writer writer) {
      super(writer);
    }

  }

  static class MaxXorTree {
    private Node root;
    private int maxBit;

    public MaxXorTree(int maxBit) {
      this.maxBit = maxBit;
      this.root = new Node();
    }

    public void insert(int value) {
      update(root, value, 1, this.maxBit);
    }

    public void remove(int value) {
      update(root, value, -1, this.maxBit);
    }

    public int query(int value) {
      return query(root, value, this.maxBit);
    }

    private void update(Node node, int value, int diff, int bit) {
      node.count += diff;
      if (bit == -1) return;

      if (node.left == null) {
        node.left = new Node();
      }
      if (node.right == null) {
        node.right = new Node();
      }

      if ((value & (1 << bit)) == 0) {
        update(node.right, value, diff, bit - 1);
      } else {
        update(node.left, value, diff, bit - 1);
      }
    }

    private int query(Node node, int value, int bit) {
      if (bit == -1) {
        return 0;
      }

      if ((value & (1 << bit)) == 0) {
        if (node.left.count > 0) {
          return query(node.left, value, bit - 1) + (1 << bit);
        } else {
          return query(node.right, value, bit - 1);
        }
      } else {
        if (node.right.count > 0) {
          return query(node.right, value, bit - 1);
        } else {
          return query(node.left, value, bit - 1) + (1 << bit);
        }
      }
    }

    class Node {
      Node left;
      Node right;
      int count;

    }

  }
}

