#include <bits/stdc++.h>
using namespace std;
bool b[31];
struct trie {
  trie* nt[2];
  int tot;
  trie() {
    nt[0] = nt[1] = NULL;
    tot = 0;
  }
};
trie* root = new trie();
void insert(trie* cur, int idx) {
  if (idx == -1)
    return;
  else {
    int x = b[idx];
    if (cur->nt[x] == NULL) cur->nt[x] = new trie();
    cur->nt[x]->tot++;
    insert(cur->nt[x], idx - 1);
  }
}
void del(trie* cur, int idx) {
  if (idx == -1)
    return;
  else {
    int x = b[idx];
    del(cur->nt[x], idx - 1);
    cur->nt[x]->tot--;
    if (cur->nt[x]->tot == 0) cur->nt[x] = NULL;
  }
}
int query(trie* cur, int idx) {
  if (idx == -1)
    return 0;
  else {
    int x = 1 - b[idx];
    int add = 1 << idx;
    if (cur->nt[x] == NULL) x = 1 - x, add = 0;
    return query(cur->nt[x], idx - 1) + add;
  }
}
int main() {
  insert(root, 30);
  int q;
  scanf("%d", &q);
  while (q--) {
    char s[2];
    int x;
    scanf("%s%d", s, &x);
    for (int i = 0; i <= 30; i++) {
      b[i] = x % 2;
      x /= 2;
    }
    if (s[0] == '+')
      insert(root, 30);
    else if (s[0] == '-')
      del(root, 30);
    else
      printf("%d\n", query(root, 30));
  }
}

### Prompt

In CPP, your task is to solve 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;
bool b[31];
struct trie {
  trie* nt[2];
  int tot;
  trie() {
    nt[0] = nt[1] = NULL;
    tot = 0;
  }
};
trie* root = new trie();
void insert(trie* cur, int idx) {
  if (idx == -1)
    return;
  else {
    int x = b[idx];
    if (cur->nt[x] == NULL) cur->nt[x] = new trie();
    cur->nt[x]->tot++;
    insert(cur->nt[x], idx - 1);
  }
}
void del(trie* cur, int idx) {
  if (idx == -1)
    return;
  else {
    int x = b[idx];
    del(cur->nt[x], idx - 1);
    cur->nt[x]->tot--;
    if (cur->nt[x]->tot == 0) cur->nt[x] = NULL;
  }
}
int query(trie* cur, int idx) {
  if (idx == -1)
    return 0;
  else {
    int x = 1 - b[idx];
    int add = 1 << idx;
    if (cur->nt[x] == NULL) x = 1 - x, add = 0;
    return query(cur->nt[x], idx - 1) + add;
  }
}
int main() {
  insert(root, 30);
  int q;
  scanf("%d", &q);
  while (q--) {
    char s[2];
    int x;
    scanf("%s%d", s, &x);
    for (int i = 0; i <= 30; i++) {
      b[i] = x % 2;
      x /= 2;
    }
    if (s[0] == '+')
      insert(root, 30);
    else if (s[0] == '-')
      del(root, 30);
    else
      printf("%d\n", query(root, 30));
  }
}

```