#include <bits/stdc++.h>
using namespace std;
typedef struct node {
  struct node* b[3];
  int flag[3];
} node;
node* root;
vector<int> ans;
int bit[32], bit_n[32];
void calc(int u) {
  memset(bit_n, 0, sizeof(bit_n));
  memset(bit, 0, sizeof(bit));
  int j = 0, num;
  for (num = u; num > 0; num = num / 2) bit_n[j++] = num % 2;
  for (int i = 0; i < 32; i++) bit[i] = bit_n[31 - i];
}
void insert(int u) {
  node* head;
  head = root;
  calc(u);
  for (int i = 0; i < 32; i++) {
    if (head->b[bit[i]] == NULL) {
      node* temp;
      temp = (node*)malloc(sizeof(node));
      for (int j = 0; j < 3; j++) temp->b[j] = NULL, temp->flag[j] = 0;
      head->b[bit[i]] = temp;
    }
    head->flag[bit[i]]++;
    head = head->b[bit[i]];
  }
  return;
}
void del(int u) {
  node* head;
  head = root;
  calc(u);
  for (int i = 0; i < 32; i++) {
    head->flag[bit[i]]--;
    head = head->b[bit[i]];
  }
  return;
}
void search(int u) {
  calc(u);
  node* head;
  head = root;
  for (int i = 0; i < 32; i++) {
    if (bit[i] == 1) {
      if (head->flag[0])
        ans.push_back(1), head = head->b[0];
      else
        ans.push_back(0), head = head->b[1];
    } else {
      if (head->flag[1])
        ans.push_back(1), head = head->b[1];
      else
        ans.push_back(0), head = head->b[0];
    }
  }
}
int main() {
  root = (node*)malloc(sizeof(node));
  for (int i = 0; i < 3; i++) root->b[i] = NULL, root->flag[i] = 0;
  int n;
  cin >> n;
  insert(0);
  char a;
  int num;
  for (int i = 0; i < n; i++) {
    int calc = 0;
    cin >> a >> num;
    if (a == '+')
      insert(num);
    else if (a == '-')
      del(num);
    else {
      ans.clear();
      search(num);
      for (int i = 0; i < ans.size(); i++) calc += (pow(2, 31 - i) * ans[i]);
      cout << calc << "\n";
    }
  }
  return 0;
}

### Prompt

In CPP, your task is to solve 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;
typedef struct node {
  struct node* b[3];
  int flag[3];
} node;
node* root;
vector<int> ans;
int bit[32], bit_n[32];
void calc(int u) {
  memset(bit_n, 0, sizeof(bit_n));
  memset(bit, 0, sizeof(bit));
  int j = 0, num;
  for (num = u; num > 0; num = num / 2) bit_n[j++] = num % 2;
  for (int i = 0; i < 32; i++) bit[i] = bit_n[31 - i];
}
void insert(int u) {
  node* head;
  head = root;
  calc(u);
  for (int i = 0; i < 32; i++) {
    if (head->b[bit[i]] == NULL) {
      node* temp;
      temp = (node*)malloc(sizeof(node));
      for (int j = 0; j < 3; j++) temp->b[j] = NULL, temp->flag[j] = 0;
      head->b[bit[i]] = temp;
    }
    head->flag[bit[i]]++;
    head = head->b[bit[i]];
  }
  return;
}
void del(int u) {
  node* head;
  head = root;
  calc(u);
  for (int i = 0; i < 32; i++) {
    head->flag[bit[i]]--;
    head = head->b[bit[i]];
  }
  return;
}
void search(int u) {
  calc(u);
  node* head;
  head = root;
  for (int i = 0; i < 32; i++) {
    if (bit[i] == 1) {
      if (head->flag[0])
        ans.push_back(1), head = head->b[0];
      else
        ans.push_back(0), head = head->b[1];
    } else {
      if (head->flag[1])
        ans.push_back(1), head = head->b[1];
      else
        ans.push_back(0), head = head->b[0];
    }
  }
}
int main() {
  root = (node*)malloc(sizeof(node));
  for (int i = 0; i < 3; i++) root->b[i] = NULL, root->flag[i] = 0;
  int n;
  cin >> n;
  insert(0);
  char a;
  int num;
  for (int i = 0; i < n; i++) {
    int calc = 0;
    cin >> a >> num;
    if (a == '+')
      insert(num);
    else if (a == '-')
      del(num);
    else {
      ans.clear();
      search(num);
      for (int i = 0; i < ans.size(); i++) calc += (pow(2, 31 - i) * ans[i]);
      cout << calc << "\n";
    }
  }
  return 0;
}

```