#include <bits/stdc++.h>
using namespace std;
const int MOD = 1e9 + 7;
const int INF = 0x3f3f3f3f;
const double PI = acos(-1.0);
const int MAXN = 2e5 + 5;
int a[MAXN * 35][2], cnt[MAXN * 35 * 2], root, top, q;
void Insert(int v, int c) {
  int cur = root;
  for (int i = 31; i >= 0; --i) {
    int x = (v >> i) & 1;
    if (a[cur][x] == 0) a[cur][x] = ++top;
    cur = a[cur][x];
    cnt[cur] += c;
  }
}
int Query(int v) {
  int cur = root, res = 0;
  for (int i = 31; i >= 0; --i) {
    int x = (v >> i) & 1;
    x ^= 1;
    if (a[cur][x] && cnt[a[cur][x]]) {
      res |= (1 << i);
      cur = a[cur][x];
    } else
      cur = a[cur][x ^ 1];
  }
  return res;
}
int main(int argc, char const *argv[]) {
  Insert(0, 1);
  scanf("%d", &q);
  while (q--) {
    char op[10];
    scanf("%s", op);
    if (op[0] == '+') {
      int x;
      scanf("%d", &x);
      Insert(x, 1);
    } else if (op[0] == '-') {
      int x;
      scanf("%d", &x);
      Insert(x, -1);
    } else if (op[0] == '?') {
      int x;
      scanf("%d", &x);
      printf("%d\n", Query(x));
    }
  }
  return 0;
}

### Prompt

Please provide a CPP coded solution 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;
const int MOD = 1e9 + 7;
const int INF = 0x3f3f3f3f;
const double PI = acos(-1.0);
const int MAXN = 2e5 + 5;
int a[MAXN * 35][2], cnt[MAXN * 35 * 2], root, top, q;
void Insert(int v, int c) {
  int cur = root;
  for (int i = 31; i >= 0; --i) {
    int x = (v >> i) & 1;
    if (a[cur][x] == 0) a[cur][x] = ++top;
    cur = a[cur][x];
    cnt[cur] += c;
  }
}
int Query(int v) {
  int cur = root, res = 0;
  for (int i = 31; i >= 0; --i) {
    int x = (v >> i) & 1;
    x ^= 1;
    if (a[cur][x] && cnt[a[cur][x]]) {
      res |= (1 << i);
      cur = a[cur][x];
    } else
      cur = a[cur][x ^ 1];
  }
  return res;
}
int main(int argc, char const *argv[]) {
  Insert(0, 1);
  scanf("%d", &q);
  while (q--) {
    char op[10];
    scanf("%s", op);
    if (op[0] == '+') {
      int x;
      scanf("%d", &x);
      Insert(x, 1);
    } else if (op[0] == '-') {
      int x;
      scanf("%d", &x);
      Insert(x, -1);
    } else if (op[0] == '?') {
      int x;
      scanf("%d", &x);
      printf("%d\n", Query(x));
    }
  }
  return 0;
}

```