#include <bits/stdc++.h>
using namespace std;
struct trieNode {
  trieNode *children[2];
  int counter;
  trieNode() {
    counter = 0;
    for (int i = 0; i < 2; i++) children[i] = NULL;
  }
} *root = new trieNode();
void add(string s, int delta) {
  trieNode *cur = root;
  int n = s.length();
  for (int i = 0; i < n; i++) {
    int idx = s[i] - '0';
    if (cur->children[idx] == NULL) cur->children[idx] = new trieNode();
    cur = cur->children[idx];
    cur->counter += delta;
  }
}
int query(string s) {
  int n = s.length();
  int ret = 0;
  trieNode *cur = root;
  for (int i = 0; i < n; i++) {
    int idx = s[i] - '0';
    idx = 1 - idx;
    if (cur->children[idx] != NULL && cur->children[idx]->counter != 0) {
      ret += (1 << (n - i - 1));
      cur = cur->children[idx];
    } else {
      cur = cur->children[1 - idx];
    }
  }
  return ret;
}
string toBinary(int x) {
  string ret = "";
  while (x) {
    if (x % 2 == 0)
      ret = "0" + ret;
    else
      ret = "1" + ret;
    x /= 2;
  }
  while (ret.length() != 30) ret = "0" + ret;
  return ret;
}
int main() {
  int q;
  cin >> q;
  add(toBinary(0), 1);
  while (q--) {
    char type;
    int x;
    cin >> type >> x;
    if (type == '+') add(toBinary(x), 1);
    if (type == '-') add(toBinary(x), -1);
    if (type == '?') cout << query(toBinary(x)) << '\n';
  }
}

### Prompt

Your challenge is to write a cpp solution to the following problem:

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>.

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
struct trieNode {
  trieNode *children[2];
  int counter;
  trieNode() {
    counter = 0;
    for (int i = 0; i < 2; i++) children[i] = NULL;
  }
} *root = new trieNode();
void add(string s, int delta) {
  trieNode *cur = root;
  int n = s.length();
  for (int i = 0; i < n; i++) {
    int idx = s[i] - '0';
    if (cur->children[idx] == NULL) cur->children[idx] = new trieNode();
    cur = cur->children[idx];
    cur->counter += delta;
  }
}
int query(string s) {
  int n = s.length();
  int ret = 0;
  trieNode *cur = root;
  for (int i = 0; i < n; i++) {
    int idx = s[i] - '0';
    idx = 1 - idx;
    if (cur->children[idx] != NULL && cur->children[idx]->counter != 0) {
      ret += (1 << (n - i - 1));
      cur = cur->children[idx];
    } else {
      cur = cur->children[1 - idx];
    }
  }
  return ret;
}
string toBinary(int x) {
  string ret = "";
  while (x) {
    if (x % 2 == 0)
      ret = "0" + ret;
    else
      ret = "1" + ret;
    x /= 2;
  }
  while (ret.length() != 30) ret = "0" + ret;
  return ret;
}
int main() {
  int q;
  cin >> q;
  add(toBinary(0), 1);
  while (q--) {
    char type;
    int x;
    cin >> type >> x;
    if (type == '+') add(toBinary(x), 1);
    if (type == '-') add(toBinary(x), -1);
    if (type == '?') cout << query(toBinary(x)) << '\n';
  }
}

```