#include <bits/stdc++.h>
using namespace std;
struct node {
  int freq;
  node *next[2];
  node() {
    freq = 0;
    for (int i = 0; i < 2; i++) {
      next[i] = NULL;
    }
  }
} * root;
void insert(int n, int val) {
  node *cur = root;
  for (int i = 31; i >= 0; i--) {
    int id = (n & (1 << i));
    id = id >> i;
    if (cur->next[id] == NULL) {
      cur->next[id] = new node();
    }
    cur = cur->next[id];
    cur->freq += val;
  }
}
int search(int n) {
  node *cur = root;
  int ans = 0;
  for (int i = 31; i >= 0; i--) {
    int id = n & (1 << i);
    id = id >> i;
    if (cur->next[id ^ 1] && cur->next[id ^ 1]->freq) {
      ans += (1 << i);
      cur = cur->next[id ^ 1];
    } else {
      cur = cur->next[id];
    }
  }
  return ans;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int i, j, k, l, m, n, p, q;
  char c;
  cin >> n;
  root = new node();
  insert(0, 1);
  for (i = 0; i < n; i++) {
    cin >> c >> p;
    if (c == '+') {
      insert(p, 1);
    } else if (c == '-') {
      insert(p, -1);
    } else {
      cout << search(p) << endl;
    }
  }
  return 0;
}

### Prompt

Generate 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 freq;
  node *next[2];
  node() {
    freq = 0;
    for (int i = 0; i < 2; i++) {
      next[i] = NULL;
    }
  }
} * root;
void insert(int n, int val) {
  node *cur = root;
  for (int i = 31; i >= 0; i--) {
    int id = (n & (1 << i));
    id = id >> i;
    if (cur->next[id] == NULL) {
      cur->next[id] = new node();
    }
    cur = cur->next[id];
    cur->freq += val;
  }
}
int search(int n) {
  node *cur = root;
  int ans = 0;
  for (int i = 31; i >= 0; i--) {
    int id = n & (1 << i);
    id = id >> i;
    if (cur->next[id ^ 1] && cur->next[id ^ 1]->freq) {
      ans += (1 << i);
      cur = cur->next[id ^ 1];
    } else {
      cur = cur->next[id];
    }
  }
  return ans;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int i, j, k, l, m, n, p, q;
  char c;
  cin >> n;
  root = new node();
  insert(0, 1);
  for (i = 0; i < n; i++) {
    cin >> c >> p;
    if (c == '+') {
      insert(p, 1);
    } else if (c == '-') {
      insert(p, -1);
    } else {
      cout << search(p) << endl;
    }
  }
  return 0;
}

```