#include <bits/stdc++.h>
using namespace std;
const int inf = 0x3f3f3f3f;
int tot = 0;
int ch[5000001][2];
int s[5000001];
void insert(int x) {
  int Root = 0;
  for (int i = 30; i >= 0; i--) {
    int tmp = (x >> i) & 1;
    if (!ch[Root][tmp]) {
      ch[Root][tmp] = ++tot;
      s[tot] = 0;
    }
    Root = ch[Root][tmp];
    ++s[Root];
  }
}
void del(int x) {
  int Root = 0;
  for (int i = 30; i >= 0; i--) {
    int tmp = (x >> i) & 1;
    Root = ch[Root][tmp];
    --s[Root];
  }
}
int query(int x) {
  int Root = 0, ans = 0;
  for (int i = 30; i >= 0; i--) {
    int tmp = (x >> i) & 1;
    if (s[ch[Root][tmp ^ 1]])
      ans += (1 << i), Root = ch[Root][tmp ^ 1];
    else
      Root = ch[Root][tmp];
  }
  return ans;
}
int q, x;
char str[101];
int main() {
  scanf("%d", &q);
  insert(0);
  while (q--) {
    scanf("%s", str);
    scanf("%d", &x);
    if (str[0] == '+')
      insert(x);
    else if (str[0] == '-')
      del(x);
    else
      printf("%d\n", query(x));
  }
  return 0;
}

### Prompt

Your task is to create 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 inf = 0x3f3f3f3f;
int tot = 0;
int ch[5000001][2];
int s[5000001];
void insert(int x) {
  int Root = 0;
  for (int i = 30; i >= 0; i--) {
    int tmp = (x >> i) & 1;
    if (!ch[Root][tmp]) {
      ch[Root][tmp] = ++tot;
      s[tot] = 0;
    }
    Root = ch[Root][tmp];
    ++s[Root];
  }
}
void del(int x) {
  int Root = 0;
  for (int i = 30; i >= 0; i--) {
    int tmp = (x >> i) & 1;
    Root = ch[Root][tmp];
    --s[Root];
  }
}
int query(int x) {
  int Root = 0, ans = 0;
  for (int i = 30; i >= 0; i--) {
    int tmp = (x >> i) & 1;
    if (s[ch[Root][tmp ^ 1]])
      ans += (1 << i), Root = ch[Root][tmp ^ 1];
    else
      Root = ch[Root][tmp];
  }
  return ans;
}
int q, x;
char str[101];
int main() {
  scanf("%d", &q);
  insert(0);
  while (q--) {
    scanf("%s", str);
    scanf("%d", &x);
    if (str[0] == '+')
      insert(x);
    else if (str[0] == '-')
      del(x);
    else
      printf("%d\n", query(x));
  }
  return 0;
}

```