#include <bits/stdc++.h>
using namespace std;
struct node {
  int val, val2;
  node* a[2];
};
node* newnode() {
  node* n = new node;
  n->a[0] = n->a[1] = NULL;
  n->val = 0;
  return n;
};
void insert(node*& root, int num) {
  bool val;
  node* temp = root;
  for (int i = 32 - 1; i >= 0; i--) {
    val = num & (1 << i);
    if (temp->a[val] == NULL) temp->a[val] = newnode();
    temp = temp->a[val];
  }
  temp->val2 = num;
  temp->val = temp->val + num;
}
int search(node* root, int num) {
  bool val;
  for (int i = 32 - 1; i >= 0; i--) {
    val = num & (1 << i);
    if (root->a[1 - val] != NULL)
      root = root->a[1 - val];
    else if (root->a[val] != NULL)
      root = root->a[val];
  }
  return num ^ root->val2;
}
void del(node*& root) {
  if (root != NULL) {
    del(root->a[0]);
    delete root;
    del(root->a[1]);
  }
}
void deletetree(node* temp, int num, int i) {
  bool val, flag;
  node* tobe;
  int dir;
  for (i = 32 - 1; i >= 0; i--) {
    val = num & (1 << i);
    if (temp->a[val] != NULL) {
      if (temp->a[0] != NULL & temp->a[1] != NULL) {
        dir = val;
        tobe = temp;
      }
      temp = temp->a[val];
      if (temp->val != 0 && temp->val % num == 0) {
        flag = true;
        temp->val -= num;
      }
    }
  }
  if (flag && temp->val == 0) {
    temp->val2 = 0;
    if (dir == 1) {
      tobe->a[1] = NULL;
    } else {
      tobe->a[0] = NULL;
    }
  }
}
int main() {
  node* root = new node;
  int t;
  char c;
  int num;
  cin >> t;
  insert(root, 0);
  while (t--) {
    cin >> c >> num;
    if (c == '+')
      insert(root, num);
    else if (c == '-')
      deletetree(root, num, 32);
    else if (c == '?')
      cout << search(root, num) << endl;
  }
}

### Prompt

Develop a solution in CPP to the problem described below:

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 {
  int val, val2;
  node* a[2];
};
node* newnode() {
  node* n = new node;
  n->a[0] = n->a[1] = NULL;
  n->val = 0;
  return n;
};
void insert(node*& root, int num) {
  bool val;
  node* temp = root;
  for (int i = 32 - 1; i >= 0; i--) {
    val = num & (1 << i);
    if (temp->a[val] == NULL) temp->a[val] = newnode();
    temp = temp->a[val];
  }
  temp->val2 = num;
  temp->val = temp->val + num;
}
int search(node* root, int num) {
  bool val;
  for (int i = 32 - 1; i >= 0; i--) {
    val = num & (1 << i);
    if (root->a[1 - val] != NULL)
      root = root->a[1 - val];
    else if (root->a[val] != NULL)
      root = root->a[val];
  }
  return num ^ root->val2;
}
void del(node*& root) {
  if (root != NULL) {
    del(root->a[0]);
    delete root;
    del(root->a[1]);
  }
}
void deletetree(node* temp, int num, int i) {
  bool val, flag;
  node* tobe;
  int dir;
  for (i = 32 - 1; i >= 0; i--) {
    val = num & (1 << i);
    if (temp->a[val] != NULL) {
      if (temp->a[0] != NULL & temp->a[1] != NULL) {
        dir = val;
        tobe = temp;
      }
      temp = temp->a[val];
      if (temp->val != 0 && temp->val % num == 0) {
        flag = true;
        temp->val -= num;
      }
    }
  }
  if (flag && temp->val == 0) {
    temp->val2 = 0;
    if (dir == 1) {
      tobe->a[1] = NULL;
    } else {
      tobe->a[0] = NULL;
    }
  }
}
int main() {
  node* root = new node;
  int t;
  char c;
  int num;
  cin >> t;
  insert(root, 0);
  while (t--) {
    cin >> c >> num;
    if (c == '+')
      insert(root, num);
    else if (c == '-')
      deletetree(root, num, 32);
    else if (c == '?')
      cout << search(root, num) << endl;
  }
}

```