#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1e5 + 5;
using ll = long long;
const int bits = 29;
struct Node {
  int cnt = 0;
  array<int, 2> child = {-1, -1};
};
vector<Node> trie;
void create_children(int idx) {
  for (int i = 0; i < 2; i++) {
    if (trie[idx].child[i] > -1) return;
    trie[idx].child[i] = int(trie.size());
    trie.emplace_back();
  }
}
void modify(int x, int delta) {
  int idx = 1;
  for (int bit = bits; bit >= 0; bit--) {
    if (delta > 0) create_children(idx);
    idx = trie[idx].child[(x >> bit) & 1];
    trie[idx].cnt += delta;
  }
}
int query(int x) {
  int idx = 1, res = 0;
  for (int bit = bits; bit >= 0; bit--) {
    int next = (~x >> bit) & 1;
    int optimal = trie[idx].child[next];
    int nonOptimal = trie[idx].child[next ^ 1];
    if (optimal == -1 && nonOptimal == -1) break;
    if (trie[optimal].cnt > 0) {
      idx = optimal;
      res |= 1 << bit;
    } else if (trie[nonOptimal].cnt > 0) {
      idx = nonOptimal;
    } else
      break;
  }
  return res;
}
void solve() {
  int q;
  cin >> q;
  trie.emplace_back();
  trie.emplace_back();
  while (q--) {
    char type;
    int x;
    cin >> type >> x;
    if (type == '+')
      modify(x, 1);
    else if (type == '-')
      modify(x, -1);
    else
      cout << max(x, query(x)) << "\n";
  }
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int tc = 1;
  while (tc--) solve();
}

### Prompt

Please formulate 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;
const int MAXN = 1e5 + 5;
using ll = long long;
const int bits = 29;
struct Node {
  int cnt = 0;
  array<int, 2> child = {-1, -1};
};
vector<Node> trie;
void create_children(int idx) {
  for (int i = 0; i < 2; i++) {
    if (trie[idx].child[i] > -1) return;
    trie[idx].child[i] = int(trie.size());
    trie.emplace_back();
  }
}
void modify(int x, int delta) {
  int idx = 1;
  for (int bit = bits; bit >= 0; bit--) {
    if (delta > 0) create_children(idx);
    idx = trie[idx].child[(x >> bit) & 1];
    trie[idx].cnt += delta;
  }
}
int query(int x) {
  int idx = 1, res = 0;
  for (int bit = bits; bit >= 0; bit--) {
    int next = (~x >> bit) & 1;
    int optimal = trie[idx].child[next];
    int nonOptimal = trie[idx].child[next ^ 1];
    if (optimal == -1 && nonOptimal == -1) break;
    if (trie[optimal].cnt > 0) {
      idx = optimal;
      res |= 1 << bit;
    } else if (trie[nonOptimal].cnt > 0) {
      idx = nonOptimal;
    } else
      break;
  }
  return res;
}
void solve() {
  int q;
  cin >> q;
  trie.emplace_back();
  trie.emplace_back();
  while (q--) {
    char type;
    int x;
    cin >> type >> x;
    if (type == '+')
      modify(x, 1);
    else if (type == '-')
      modify(x, -1);
    else
      cout << max(x, query(x)) << "\n";
  }
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int tc = 1;
  while (tc--) solve();
}

```