#include <bits/stdc++.h>
using namespace std;
struct node {
  node* next[2];
  int child;
  node() {
    child = 0;
    next[1] = next[0] = 0;
  }
} * root;
void Insert(int tmp) {
  node* curr = root;
  root->child += 1;
  for (int i = 31; i >= 0; i--) {
    bool val = (tmp & (1 << i));
    if (curr->next[val] == 0) {
      curr->next[val] = new node();
    }
    curr = curr->next[val];
    curr->child += 1;
  }
  curr = root;
  for (int i = 31; i >= 0; i--) {
    bool val = (tmp & (1 << i));
    curr = curr->next[val];
  }
}
void Delete(int tmp) {
  node* curr = root;
  root->child -= 1;
  for (int i = 31; i >= 0; i--) {
    bool val = (tmp & (1 << i));
    curr = curr->next[val];
    curr->child -= 1;
  }
}
int Query(int tmp) {
  node* curr = root;
  int ans = 0;
  for (int i = 31; i >= 0; i--) {
    ans <<= 1;
    int bit = !(tmp & (1 << i));
    if (curr->next[bit] == 0 || curr->next[bit]->child == 0) bit ^= 1;
    curr = curr->next[bit];
    ans |= bit;
  }
  return (ans ^ tmp);
}
int q;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  root = new node();
  Insert(0);
  cin >> q;
  while (q--) {
    string s, s1;
    int tmp;
    cin >> s >> tmp;
    if (s == "+")
      Insert(tmp);
    else if (s == "-")
      Delete(tmp);
    else
      cout << Query(tmp) << '\n';
  }
  cout << endl;
  return 0;
}

### Prompt

Please formulate 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 node {
  node* next[2];
  int child;
  node() {
    child = 0;
    next[1] = next[0] = 0;
  }
} * root;
void Insert(int tmp) {
  node* curr = root;
  root->child += 1;
  for (int i = 31; i >= 0; i--) {
    bool val = (tmp & (1 << i));
    if (curr->next[val] == 0) {
      curr->next[val] = new node();
    }
    curr = curr->next[val];
    curr->child += 1;
  }
  curr = root;
  for (int i = 31; i >= 0; i--) {
    bool val = (tmp & (1 << i));
    curr = curr->next[val];
  }
}
void Delete(int tmp) {
  node* curr = root;
  root->child -= 1;
  for (int i = 31; i >= 0; i--) {
    bool val = (tmp & (1 << i));
    curr = curr->next[val];
    curr->child -= 1;
  }
}
int Query(int tmp) {
  node* curr = root;
  int ans = 0;
  for (int i = 31; i >= 0; i--) {
    ans <<= 1;
    int bit = !(tmp & (1 << i));
    if (curr->next[bit] == 0 || curr->next[bit]->child == 0) bit ^= 1;
    curr = curr->next[bit];
    ans |= bit;
  }
  return (ans ^ tmp);
}
int q;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  root = new node();
  Insert(0);
  cin >> q;
  while (q--) {
    string s, s1;
    int tmp;
    cin >> s >> tmp;
    if (s == "+")
      Insert(tmp);
    else if (s == "-")
      Delete(tmp);
    else
      cout << Query(tmp) << '\n';
  }
  cout << endl;
  return 0;
}

```