#include <bits/stdc++.h>
using namespace std;
template <class T>
inline void read(T& num) {
  bool start = false, neg = false;
  char c;
  num = 0;
  while ((c = getchar()) != EOF) {
    if (c == '-')
      start = neg = true;
    else if (c >= '0' && c <= '9') {
      start = true;
      num = num * 10 + c - '0';
    } else if (start)
      break;
  }
  if (neg) num = -num;
}
char opt[10];
const int maxn = (int)(8e6) + 5;
int ch[maxn][2];
int sum[maxn];
int idx;
inline void add(int x, int v) {
  int rt = 1;
  for (int i = (30); i >= (0); i--) {
    int c = (x >> i) & 1;
    if (!ch[rt][c]) ch[rt][c] = ++idx;
    rt = ch[rt][c];
    sum[rt] += v;
  }
}
inline int qmax(int x) {
  int rt = 1, res = 0;
  for (int i = (30); i >= (0); i--) {
    int c = (x >> i) & 1;
    c ^= 1;
    if (sum[ch[rt][c]]) {
      rt = ch[rt][c];
      res += (1 << i);
    } else
      rt = ch[rt][c ^ 1];
  }
  return res;
}
int main() {
  int q, x;
  idx = 1;
  add(0, 1);
  read(q);
  for (int i = (1); i <= (q); i++) {
    scanf("%s%d", opt, &x);
    if (opt[0] == '+')
      add(x, 1);
    else if (opt[0] == '-')
      add(x, -1);
    else
      printf("%d\n", qmax(x));
  }
  return 0;
}

### Prompt

Construct a CPP code solution to the problem outlined:

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;
template <class T>
inline void read(T& num) {
  bool start = false, neg = false;
  char c;
  num = 0;
  while ((c = getchar()) != EOF) {
    if (c == '-')
      start = neg = true;
    else if (c >= '0' && c <= '9') {
      start = true;
      num = num * 10 + c - '0';
    } else if (start)
      break;
  }
  if (neg) num = -num;
}
char opt[10];
const int maxn = (int)(8e6) + 5;
int ch[maxn][2];
int sum[maxn];
int idx;
inline void add(int x, int v) {
  int rt = 1;
  for (int i = (30); i >= (0); i--) {
    int c = (x >> i) & 1;
    if (!ch[rt][c]) ch[rt][c] = ++idx;
    rt = ch[rt][c];
    sum[rt] += v;
  }
}
inline int qmax(int x) {
  int rt = 1, res = 0;
  for (int i = (30); i >= (0); i--) {
    int c = (x >> i) & 1;
    c ^= 1;
    if (sum[ch[rt][c]]) {
      rt = ch[rt][c];
      res += (1 << i);
    } else
      rt = ch[rt][c ^ 1];
  }
  return res;
}
int main() {
  int q, x;
  idx = 1;
  add(0, 1);
  read(q);
  for (int i = (1); i <= (q); i++) {
    scanf("%s%d", opt, &x);
    if (opt[0] == '+')
      add(x, 1);
    else if (opt[0] == '-')
      add(x, -1);
    else
      printf("%d\n", qmax(x));
  }
  return 0;
}

```