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>.
//package Assignment3;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.StringTokenizer;

public class TrieProblem1 {
	static PrintWriter pw;

	public static void main(String[] args) throws IOException {
		BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
		int n = Integer.parseInt(bf.readLine());
		String s="00000000000000000000000000000000";
		Trie trie = new Trie();
		trie.insert(s.toCharArray());
		pw = new PrintWriter(System.out);
		for (int i = 0; i < n; i++) {
			StringTokenizer st = new StringTokenizer(bf.readLine());
			String sign = st.nextToken();
			String binary = Integer.toBinaryString(Integer.parseInt(st
					.nextToken()));
			int l=binary.length();
			binary=s.substring(0,32-l)+binary;
			//System.out.println(binary);
			if (sign.equals("+")) {
				// call insert
				trie.insert(binary.toCharArray());
			} else if (sign.equals("-")) {
				// call delete
				trie.delete(binary.toCharArray());

			} else {
				// ? call search
				pw.println(trie.search(binary.toCharArray()));
			}

		}
		pw.flush();pw.close();
	}

}

class Trie {
	class Node {
		int occurOne;
		int occurZero;
		boolean end;
		Node[] next;

		Node() {
			next = new Node[2];
		}
	}

	Node root;

	Trie() {
		root = new Node();
	}

	void insert(char... s) {
		int slen = s.length;
		Node cur = root;
		for (int i = 0; i < slen; i++) {
			int nextIdx = s[i] - '0';
			if (cur.next[nextIdx] == null) {
				cur.next[nextIdx] = new Node();
			}
			if (s[i] == '0')
				cur.occurZero++;
			else
				cur.occurOne++;
			cur = cur.next[nextIdx];
		}
		cur.end = true;
	}

	void delete(char... s) {
		int slen = s.length;
		Node cur = root;
		for (int i = 0; i < slen; i++) {
			int nextIdx = s[i] - '0';
			if (cur.next[nextIdx] == null) {
				return;
			} else {
				if (s[i] == '0')
					cur.occurZero--;
				else
					cur.occurOne--;
			}
			cur = cur.next[nextIdx];
		}

	}

	int search(char... s) {
		StringBuilder sb = new StringBuilder();
		int slen = s.length;
		Node cur = root;
		for (int i = 0; i < slen; i++) {
			int nextIdx = '1' - s[i];
			if(i== 27){
			//	System.out.println("here");
			}
			boolean change=false;
			if (nextIdx == 1) {
				if (cur.occurOne > 0) {
					sb.append('1');
				}
				else{
					nextIdx=0;
					change=true;
				}
			}
			if (nextIdx == 0){
				if (cur.occurZero > 0) {
					if(!change)
						sb.append('1');
					else
						sb.append('0');
				}
				else{
					if(cur.occurOne > 0 ){
						nextIdx=1;
						if(change)
							sb.append('1');
						else
							sb.append('0');
					}
					else
						break;
				}
			}

			// if(cur.next[nextIdx] != null ){
			// sb.append((nextIdx+(int)'0'));
			// }
			// else if (cur.next[(s[i]-'0')] != null){
			// nextIdx=s[i]-'0';
			// sb.append(s[i]);
			// }
			// else{
			//
			// }
			cur = cur.next[nextIdx];
		}
		//System.out.println(sb.toString());
		return Integer.parseInt(sb.toString(),2);
	}

	boolean search2(char... s) {
		int slen = s.length;
		Node cur = root;
		for (int i = slen - 1; i >= 0; i--) {
			int nextIdx = s[i] - '0';
			if (cur.next[nextIdx] == null)
				return false;
			cur = cur.next[nextIdx];
		}
		return cur.end;
	}

}
