#include <bits/stdc++.h>
using namespace std;
struct Node {
  int cnt;
  Node* child[2];
  Node() {
    cnt = 0;
    child[0] = child[1] = NULL;
  }
  Node* insert(Node* root, unsigned val, int bit) {
    root->cnt++;
    if (bit < 0) return root;
    int v = !!(val & (1U << bit));
    if (!root->child[v]) {
      root->child[v] = new Node();
    }
    root->child[v] = root->child[v]->insert(root->child[v], val, bit - 1);
    return root;
  }
  Node* erase(Node* root, unsigned val, int bit) {
    root->cnt--;
    if (root->cnt == 0) {
      delete root;
      return NULL;
    }
    if (bit < 0) return root;
    int v = !!(val & (1U << bit));
    root->child[v] = root->child[v]->erase(root->child[v], val, bit - 1);
    return root;
  }
};
int cnt(Node* v) {
  if (v == NULL) return 0;
  return v->cnt;
}
unsigned query(Node* root, unsigned val, int bit) {
  if (bit < 0) return 0;
  int v = !(val & (1U << bit));
  if (cnt(root->child[v]))
    return (1U << bit) | query(root->child[v], val, bit - 1);
  return query(root->child[!v], val, bit - 1);
}
Node* root = new Node();
int main() {
  char s[10];
  root->insert(root, 0, 31);
  int q;
  unsigned x;
  scanf("%d", &q);
  while (q--) {
    scanf("%s %u", s, &x);
    if (s[0] == '+') {
      root->insert(root, x, 31);
    } else if (s[0] == '-') {
      root->erase(root, x, 31);
    } else {
      printf("%u\n", query(root, x, 31));
    }
  }
  return 0;
}

### Prompt

Construct a CPP code solution to the problem outlined:

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 cnt;
  Node* child[2];
  Node() {
    cnt = 0;
    child[0] = child[1] = NULL;
  }
  Node* insert(Node* root, unsigned val, int bit) {
    root->cnt++;
    if (bit < 0) return root;
    int v = !!(val & (1U << bit));
    if (!root->child[v]) {
      root->child[v] = new Node();
    }
    root->child[v] = root->child[v]->insert(root->child[v], val, bit - 1);
    return root;
  }
  Node* erase(Node* root, unsigned val, int bit) {
    root->cnt--;
    if (root->cnt == 0) {
      delete root;
      return NULL;
    }
    if (bit < 0) return root;
    int v = !!(val & (1U << bit));
    root->child[v] = root->child[v]->erase(root->child[v], val, bit - 1);
    return root;
  }
};
int cnt(Node* v) {
  if (v == NULL) return 0;
  return v->cnt;
}
unsigned query(Node* root, unsigned val, int bit) {
  if (bit < 0) return 0;
  int v = !(val & (1U << bit));
  if (cnt(root->child[v]))
    return (1U << bit) | query(root->child[v], val, bit - 1);
  return query(root->child[!v], val, bit - 1);
}
Node* root = new Node();
int main() {
  char s[10];
  root->insert(root, 0, 31);
  int q;
  unsigned x;
  scanf("%d", &q);
  while (q--) {
    scanf("%s %u", s, &x);
    if (s[0] == '+') {
      root->insert(root, x, 31);
    } else if (s[0] == '-') {
      root->erase(root, x, 31);
    } else {
      printf("%u\n", query(root, x, 31));
    }
  }
  return 0;
}

```