#include <bits/stdc++.h>
using namespace std;
struct Node {
  struct Node *l, *r;
  int val;
  Node() {
    this->val = 0;
    this->l = NULL;
    this->r = NULL;
  }
};
void insert(struct Node *node, int bit, int num, int addsub) {
  if (bit < 0) return;
  if (num & (1 << bit)) {
    if (node->r == NULL) node->r = new Node();
    node->r->val += addsub;
    insert(node->r, bit - 1, num, addsub);
  } else {
    if (node->l == NULL) node->l = new Node();
    node->l->val += addsub;
    insert(node->l, bit - 1, num, addsub);
  }
}
long long query(struct Node *node, int bit, int num) {
  if (bit < 0 || node == NULL) return 0;
  if (num & (1 << bit)) {
    if (node->l != NULL && node->l->val > 0)
      return (1LL << bit) + query(node->l, bit - 1, num);
    else
      return query(node->r, bit - 1, num);
  } else {
    if (node->r != NULL && node->r->val > 0)
      return (1LL << bit) + query(node->r, bit - 1, num);
    else
      return query(node->l, bit - 1, num);
  }
}
struct Node *root = NULL;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int t, i, j, n, m, bits = 30;
  root = new Node();
  insert(root, bits, 0, 1);
  long long ans = 0;
  cin >> n;
  while (n--) {
    char s;
    cin >> s >> m;
    if (s == '+') {
      insert(root, bits, m, 1);
    } else if (s == '-') {
      insert(root, bits, m, -1);
    } else {
      ans = query(root, bits, m);
      cout << ans << "\n";
    }
  }
  return 0;
}

### Prompt

Generate 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 {
  struct Node *l, *r;
  int val;
  Node() {
    this->val = 0;
    this->l = NULL;
    this->r = NULL;
  }
};
void insert(struct Node *node, int bit, int num, int addsub) {
  if (bit < 0) return;
  if (num & (1 << bit)) {
    if (node->r == NULL) node->r = new Node();
    node->r->val += addsub;
    insert(node->r, bit - 1, num, addsub);
  } else {
    if (node->l == NULL) node->l = new Node();
    node->l->val += addsub;
    insert(node->l, bit - 1, num, addsub);
  }
}
long long query(struct Node *node, int bit, int num) {
  if (bit < 0 || node == NULL) return 0;
  if (num & (1 << bit)) {
    if (node->l != NULL && node->l->val > 0)
      return (1LL << bit) + query(node->l, bit - 1, num);
    else
      return query(node->r, bit - 1, num);
  } else {
    if (node->r != NULL && node->r->val > 0)
      return (1LL << bit) + query(node->r, bit - 1, num);
    else
      return query(node->l, bit - 1, num);
  }
}
struct Node *root = NULL;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int t, i, j, n, m, bits = 30;
  root = new Node();
  insert(root, bits, 0, 1);
  long long ans = 0;
  cin >> n;
  while (n--) {
    char s;
    cin >> s >> m;
    if (s == '+') {
      insert(root, bits, m, 1);
    } else if (s == '-') {
      insert(root, bits, m, -1);
    } else {
      ans = query(root, bits, m);
      cout << ans << "\n";
    }
  }
  return 0;
}

```