#include <bits/stdc++.h>
using namespace std;
struct node {
  int val = 0;
  node *l = nullptr, *r = nullptr;
} * root;
int q, x;
char c;
node *update(node *now, int l, int r, int pos, int xx, int v) {
  if (now == nullptr) now = new node();
  if (l == r)
    now->val += v;
  else {
    int mid = l + (1 << pos) - 1;
    if (x <= mid)
      now->l = update(now->l, l, mid, pos - 1, xx, v);
    else
      now->r = update(now->r, mid + 1, r, pos - 1, xx, v);
    now->val = (now->l ? now->l->val : 0) + (now->r ? now->r->val : 0);
  }
  return now;
}
int query(node *now, int l, int r, int pos, int xx) {
  if (l == r)
    return l ^ xx;
  else {
    int mid = l + (1 << pos) - 1, on = xx & (1 << pos);
    if (on) {
      if (now->l && now->l->val) return query(now->l, l, mid, pos - 1, xx);
      return query(now->r, mid + 1, r, pos - 1, xx);
    } else {
      if (now->r && now->r->val) return query(now->r, mid + 1, r, pos - 1, xx);
      return query(now->l, l, mid, pos - 1, xx);
    }
  }
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  root = new node();
  update(root, 0, (1 << 30), 29, 0, 1);
  cin >> q;
  while (q--) {
    cin >> c >> x;
    if (c == '?')
      cout << query(root, 0, (1 << 30), 29, x) << "\n";
    else
      update(root, 0, (1 << 30), 29, x, (c == '+' ? 1 : -1));
  }
}

### 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;
struct node {
  int val = 0;
  node *l = nullptr, *r = nullptr;
} * root;
int q, x;
char c;
node *update(node *now, int l, int r, int pos, int xx, int v) {
  if (now == nullptr) now = new node();
  if (l == r)
    now->val += v;
  else {
    int mid = l + (1 << pos) - 1;
    if (x <= mid)
      now->l = update(now->l, l, mid, pos - 1, xx, v);
    else
      now->r = update(now->r, mid + 1, r, pos - 1, xx, v);
    now->val = (now->l ? now->l->val : 0) + (now->r ? now->r->val : 0);
  }
  return now;
}
int query(node *now, int l, int r, int pos, int xx) {
  if (l == r)
    return l ^ xx;
  else {
    int mid = l + (1 << pos) - 1, on = xx & (1 << pos);
    if (on) {
      if (now->l && now->l->val) return query(now->l, l, mid, pos - 1, xx);
      return query(now->r, mid + 1, r, pos - 1, xx);
    } else {
      if (now->r && now->r->val) return query(now->r, mid + 1, r, pos - 1, xx);
      return query(now->l, l, mid, pos - 1, xx);
    }
  }
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  root = new node();
  update(root, 0, (1 << 30), 29, 0, 1);
  cin >> q;
  while (q--) {
    cin >> c >> x;
    if (c == '?')
      cout << query(root, 0, (1 << 30), 29, x) << "\n";
    else
      update(root, 0, (1 << 30), 29, x, (c == '+' ? 1 : -1));
  }
}

```