#include <bits/stdc++.h>
using namespace std;
int b[50];
bool a[50];
int c[50];
int sum;
struct node {
  bool is_end;
  int prefix_count;
  struct node* child[2];
} * head;
void inti() {
  head = new node();
  head->is_end = false;
  head->prefix_count = 0;
  head->child[0] = NULL;
  head->child[1] = NULL;
}
void insertt(int num) {
  node* current = head;
  current->prefix_count++;
  int i = 0;
  while (num) {
    int temp = num % 2;
    b[i] = temp;
    num /= 2;
    i++;
  }
  int j = 0;
  for (; j < (33 - i) - 1; j++) c[j] = 0;
  for (int k = j, q = i; k < 33; k++, q--) c[k] = b[q];
  i = 0;
  while (i < 33) {
    if (current->child[c[i]] == NULL) current->child[c[i]] = new node();
    current->child[c[i]]->prefix_count++;
    current = current->child[c[i]];
    i++;
  }
  memset(c, 0, sizeof(c));
  memset(b, 0, sizeof(b));
  current->is_end = true;
}
void deletee(int num) {
  node* current = head;
  current->prefix_count--;
  int i = 0;
  while (num) {
    int temp = num % 2;
    b[i] = temp;
    num /= 2;
    i++;
  }
  int j = 0;
  for (; j < (33 - i) - 1; j++) c[j] = 0;
  for (int k = j, q = i; k < 33; k++, q--) c[k] = b[q];
  i = 0;
  while (i < 33) {
    current->child[c[i]]->prefix_count--;
    if (current->child[c[i]]->prefix_count == 0) {
      current->child[c[i]] = NULL;
      return;
    }
    current = current->child[c[i]];
    i++;
  }
  memset(c, 0, sizeof(c));
  memset(b, 0, sizeof(b));
}
long long compose_bin(int i) {
  long long num = 0;
  int j = 0;
  while (j < i) {
    if (a[j]) num += pow(2, 32 - j);
    j++;
  }
  memset(a, 0, sizeof(a));
  return num;
}
long long fuct(int num) {
  node* current = head;
  int i = 0;
  while (num) {
    int temp = num % 2;
    b[i] = temp;
    num /= 2;
    i++;
  }
  int j = 0;
  for (; j < (33 - i) - 1; j++) c[j] = 0;
  for (int k = j, q = i; k < 33; k++, q--) c[k] = b[q];
  i = 0;
  while (i < 33) {
    if (current->child[1 - c[i]] == NULL) {
      a[i] = false;
      current = current->child[c[i]];
    } else {
      a[i] = true;
      current = current->child[1 - c[i]];
    }
    i++;
  }
  memset(c, 0, sizeof(c));
  memset(b, 0, sizeof(b));
  return compose_bin(i);
}
int main() {
  int n;
  scanf("%d", &n);
  inti();
  while (n--) {
    char x;
    int num;
    cin >> x >> num;
    if (x == '+') {
      insertt(num);
      sum++;
    }
    if (x == '-') {
      deletee(num);
      sum--;
    }
    if (x == '?') {
      int temp = 0 ^ num;
      if (sum)
        cout << max(fuct(num), (long long)temp) << '\n';
      else
        cout << temp << '\n';
    }
    memset(a, 0, sizeof(a));
    memset(b, 0, sizeof(b));
    memset(c, 0, sizeof(c));
  }
  return 0;
}

### Prompt

Please create a solution in cpp 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;
int b[50];
bool a[50];
int c[50];
int sum;
struct node {
  bool is_end;
  int prefix_count;
  struct node* child[2];
} * head;
void inti() {
  head = new node();
  head->is_end = false;
  head->prefix_count = 0;
  head->child[0] = NULL;
  head->child[1] = NULL;
}
void insertt(int num) {
  node* current = head;
  current->prefix_count++;
  int i = 0;
  while (num) {
    int temp = num % 2;
    b[i] = temp;
    num /= 2;
    i++;
  }
  int j = 0;
  for (; j < (33 - i) - 1; j++) c[j] = 0;
  for (int k = j, q = i; k < 33; k++, q--) c[k] = b[q];
  i = 0;
  while (i < 33) {
    if (current->child[c[i]] == NULL) current->child[c[i]] = new node();
    current->child[c[i]]->prefix_count++;
    current = current->child[c[i]];
    i++;
  }
  memset(c, 0, sizeof(c));
  memset(b, 0, sizeof(b));
  current->is_end = true;
}
void deletee(int num) {
  node* current = head;
  current->prefix_count--;
  int i = 0;
  while (num) {
    int temp = num % 2;
    b[i] = temp;
    num /= 2;
    i++;
  }
  int j = 0;
  for (; j < (33 - i) - 1; j++) c[j] = 0;
  for (int k = j, q = i; k < 33; k++, q--) c[k] = b[q];
  i = 0;
  while (i < 33) {
    current->child[c[i]]->prefix_count--;
    if (current->child[c[i]]->prefix_count == 0) {
      current->child[c[i]] = NULL;
      return;
    }
    current = current->child[c[i]];
    i++;
  }
  memset(c, 0, sizeof(c));
  memset(b, 0, sizeof(b));
}
long long compose_bin(int i) {
  long long num = 0;
  int j = 0;
  while (j < i) {
    if (a[j]) num += pow(2, 32 - j);
    j++;
  }
  memset(a, 0, sizeof(a));
  return num;
}
long long fuct(int num) {
  node* current = head;
  int i = 0;
  while (num) {
    int temp = num % 2;
    b[i] = temp;
    num /= 2;
    i++;
  }
  int j = 0;
  for (; j < (33 - i) - 1; j++) c[j] = 0;
  for (int k = j, q = i; k < 33; k++, q--) c[k] = b[q];
  i = 0;
  while (i < 33) {
    if (current->child[1 - c[i]] == NULL) {
      a[i] = false;
      current = current->child[c[i]];
    } else {
      a[i] = true;
      current = current->child[1 - c[i]];
    }
    i++;
  }
  memset(c, 0, sizeof(c));
  memset(b, 0, sizeof(b));
  return compose_bin(i);
}
int main() {
  int n;
  scanf("%d", &n);
  inti();
  while (n--) {
    char x;
    int num;
    cin >> x >> num;
    if (x == '+') {
      insertt(num);
      sum++;
    }
    if (x == '-') {
      deletee(num);
      sum--;
    }
    if (x == '?') {
      int temp = 0 ^ num;
      if (sum)
        cout << max(fuct(num), (long long)temp) << '\n';
      else
        cout << temp << '\n';
    }
    memset(a, 0, sizeof(a));
    memset(b, 0, sizeof(b));
    memset(c, 0, sizeof(c));
  }
  return 0;
}

```