#include <bits/stdc++.h>
using namespace std;
int tail = 1;
struct vertex {
  int terminal = 0;
  int terminal_kids = 0;
  int kid0 = -1, kid1 = -1;
};
vector<vertex> trie(1);
void add(int v, int it, vector<int> &s) {
  trie[v].terminal_kids++;
  if (it == s.size()) {
    trie[v].terminal++;
    return;
  }
  int next = s[it];
  if (next == 0) {
    if (trie[v].kid0 == -1) {
      trie[v].kid0 = tail++;
      trie.push_back({});
    }
    add(trie[v].kid0, it + 1, s);
    return;
  }
  if (trie[v].kid1 == -1) {
    trie[v].kid1 = tail++;
    trie.push_back({});
  }
  add(trie[v].kid1, it + 1, s);
}
void del(int v, int it, vector<int> &s) {
  trie[v].terminal_kids--;
  if (it == s.size()) {
    trie[v].terminal--;
    return;
  }
  int next = s[it];
  if (next == 0)
    del(trie[v].kid0, it + 1, s);
  else
    del(trie[v].kid1, it + 1, s);
}
void get(int v, int it, vector<int> &s, vector<int> &ans) {
  if (trie[v].terminal_kids == 0) return;
  if (it == s.size()) return;
  int next = s[it];
  if (next == 0) {
    if (trie[v].kid1 == -1 || trie[trie[v].kid1].terminal_kids == 0) {
      ans[it] = 0;
      get(trie[v].kid0, it + 1, s, ans);
      return;
    }
    ans[it] = 1;
    get(trie[v].kid1, it + 1, s, ans);
    return;
  }
  if (trie[v].kid0 == -1 || trie[trie[v].kid0].terminal_kids == 0) {
    ans[it] = 1;
    get(trie[v].kid1, it + 1, s, ans);
    return;
  }
  ans[it] = 0;
  get(trie[v].kid0, it + 1, s, ans);
}
int main() {
  int n;
  cin >> n;
  while (n--) {
    char c;
    cin >> c;
    vector<int> num(32);
    int val;
    cin >> val;
    int copy_val = val;
    for (int it = 0; it < 32; it++) {
      num[it] = val % 2;
      val /= 2;
    }
    reverse(num.begin(), num.end());
    if (c == '+') add(0, 0, num);
    if (c == '-') del(0, 0, num);
    if (c == '?') {
      vector<int> ans(32);
      get(0, 0, num, ans);
      int answer = 0;
      for (int i = 0; i < ans.size(); i++)
        answer = answer * 2 + (ans[i] ^ num[i]);
      cout << max(answer, copy_val) << '\n';
    }
  }
  return 0;
}

### Prompt

Develop a solution in CPP to the problem described below:

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;
int tail = 1;
struct vertex {
  int terminal = 0;
  int terminal_kids = 0;
  int kid0 = -1, kid1 = -1;
};
vector<vertex> trie(1);
void add(int v, int it, vector<int> &s) {
  trie[v].terminal_kids++;
  if (it == s.size()) {
    trie[v].terminal++;
    return;
  }
  int next = s[it];
  if (next == 0) {
    if (trie[v].kid0 == -1) {
      trie[v].kid0 = tail++;
      trie.push_back({});
    }
    add(trie[v].kid0, it + 1, s);
    return;
  }
  if (trie[v].kid1 == -1) {
    trie[v].kid1 = tail++;
    trie.push_back({});
  }
  add(trie[v].kid1, it + 1, s);
}
void del(int v, int it, vector<int> &s) {
  trie[v].terminal_kids--;
  if (it == s.size()) {
    trie[v].terminal--;
    return;
  }
  int next = s[it];
  if (next == 0)
    del(trie[v].kid0, it + 1, s);
  else
    del(trie[v].kid1, it + 1, s);
}
void get(int v, int it, vector<int> &s, vector<int> &ans) {
  if (trie[v].terminal_kids == 0) return;
  if (it == s.size()) return;
  int next = s[it];
  if (next == 0) {
    if (trie[v].kid1 == -1 || trie[trie[v].kid1].terminal_kids == 0) {
      ans[it] = 0;
      get(trie[v].kid0, it + 1, s, ans);
      return;
    }
    ans[it] = 1;
    get(trie[v].kid1, it + 1, s, ans);
    return;
  }
  if (trie[v].kid0 == -1 || trie[trie[v].kid0].terminal_kids == 0) {
    ans[it] = 1;
    get(trie[v].kid1, it + 1, s, ans);
    return;
  }
  ans[it] = 0;
  get(trie[v].kid0, it + 1, s, ans);
}
int main() {
  int n;
  cin >> n;
  while (n--) {
    char c;
    cin >> c;
    vector<int> num(32);
    int val;
    cin >> val;
    int copy_val = val;
    for (int it = 0; it < 32; it++) {
      num[it] = val % 2;
      val /= 2;
    }
    reverse(num.begin(), num.end());
    if (c == '+') add(0, 0, num);
    if (c == '-') del(0, 0, num);
    if (c == '?') {
      vector<int> ans(32);
      get(0, 0, num, ans);
      int answer = 0;
      for (int i = 0; i < ans.size(); i++)
        answer = answer * 2 + (ans[i] ^ num[i]);
      cout << max(answer, copy_val) << '\n';
    }
  }
  return 0;
}

```