#include <bits/stdc++.h>
using namespace std;
struct node {
  int val = 0;
  node *c[2] = {nullptr, nullptr};
} *root = new node, *cur;
int q;
void add(int x) {
  cur = root;
  for (int i = 31; i >= 0; i--) {
    int tmp = (x >> i) & 1;
    if (cur->c[tmp] == nullptr) cur->c[tmp] = new node;
    cur = cur->c[tmp];
    cur->val++;
  }
}
void out(int x) {
  cur = root;
  for (int i = 31; i >= 0; i--) {
    int tmp = (x >> i) & 1;
    cur = cur->c[tmp];
    cur->val--;
  }
}
int get(int x) {
  cur = root;
  int ans = 0;
  for (int i = 31; i >= 0; i--) {
    int tmp = (x >> i) & 1;
    if (cur->c[1 - tmp] != nullptr && cur->c[1 - tmp]->val > 0) {
      cur = cur->c[1 - tmp];
      ans += (1 << i);
    } else
      cur = cur->c[tmp];
  }
  return ans;
}
int main() {
  cin >> q;
  char c;
  int x;
  add(0);
  while (q--) {
    cin >> c >> x;
    if (c == '+')
      add(x);
    else if (c == '-')
      out(x);
    else
      cout << get(x) << '\n';
  }
  return 0;
}

### Prompt

Your task is to create 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 {
  int val = 0;
  node *c[2] = {nullptr, nullptr};
} *root = new node, *cur;
int q;
void add(int x) {
  cur = root;
  for (int i = 31; i >= 0; i--) {
    int tmp = (x >> i) & 1;
    if (cur->c[tmp] == nullptr) cur->c[tmp] = new node;
    cur = cur->c[tmp];
    cur->val++;
  }
}
void out(int x) {
  cur = root;
  for (int i = 31; i >= 0; i--) {
    int tmp = (x >> i) & 1;
    cur = cur->c[tmp];
    cur->val--;
  }
}
int get(int x) {
  cur = root;
  int ans = 0;
  for (int i = 31; i >= 0; i--) {
    int tmp = (x >> i) & 1;
    if (cur->c[1 - tmp] != nullptr && cur->c[1 - tmp]->val > 0) {
      cur = cur->c[1 - tmp];
      ans += (1 << i);
    } else
      cur = cur->c[tmp];
  }
  return ans;
}
int main() {
  cin >> q;
  char c;
  int x;
  add(0);
  while (q--) {
    cin >> c >> x;
    if (c == '+')
      add(x);
    else if (c == '-')
      out(x);
    else
      cout << get(x) << '\n';
  }
  return 0;
}

```