#include <bits/stdc++.h>
using namespace std;
const long long mod = 1000000007;
int tree[30 * 200005][2];
int cnt[30 * 200005];
int tot = 0;
void add(int num) {
  int now = 0;
  for (int x = 30; x >= 0; x--) {
    int bit = (num >> x) & 1;
    if (!tree[now][bit]) {
      tree[now][bit] = ++tot;
    }
    now = tree[now][bit];
    cnt[now]++;
  }
}
void sub(int num) {
  int now = 0;
  for (int x = 30; x >= 0; x--) {
    int bit = (num >> x) & 1;
    now = tree[now][bit];
    cnt[now]--;
  }
}
void query(int num) {
  int now = 0;
  int anstarget = 0;
  for (int x = 30; x >= 0; x--) {
    int bit = (num >> x) & 1;
    int leftnow = tree[now][bit];
    int rightnow = tree[now][1 - bit];
    if (rightnow && cnt[rightnow] > 0) {
      if (bit == 0) anstarget |= (1 << x);
      now = rightnow;
    } else if (leftnow && cnt[leftnow] > 0) {
      if (bit == 1) anstarget |= (1 << x);
      now = leftnow;
    } else {
    }
  }
  cout << (num ^ anstarget) << endl;
}
int main() {
  memset(cnt, 0, sizeof(cnt));
  memset(tree, 0, sizeof(tree));
  int n;
  cin >> n;
  add(0);
  while (n--) {
    char s[2];
    int num;
    scanf("%s%d", s, &num);
    switch (s[0]) {
      case '+':
        add(num);
        break;
      case '-':
        sub(num);
        break;
      case '?':
        query(num);
        break;
      default:
        break;
    }
  }
  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;
const long long mod = 1000000007;
int tree[30 * 200005][2];
int cnt[30 * 200005];
int tot = 0;
void add(int num) {
  int now = 0;
  for (int x = 30; x >= 0; x--) {
    int bit = (num >> x) & 1;
    if (!tree[now][bit]) {
      tree[now][bit] = ++tot;
    }
    now = tree[now][bit];
    cnt[now]++;
  }
}
void sub(int num) {
  int now = 0;
  for (int x = 30; x >= 0; x--) {
    int bit = (num >> x) & 1;
    now = tree[now][bit];
    cnt[now]--;
  }
}
void query(int num) {
  int now = 0;
  int anstarget = 0;
  for (int x = 30; x >= 0; x--) {
    int bit = (num >> x) & 1;
    int leftnow = tree[now][bit];
    int rightnow = tree[now][1 - bit];
    if (rightnow && cnt[rightnow] > 0) {
      if (bit == 0) anstarget |= (1 << x);
      now = rightnow;
    } else if (leftnow && cnt[leftnow] > 0) {
      if (bit == 1) anstarget |= (1 << x);
      now = leftnow;
    } else {
    }
  }
  cout << (num ^ anstarget) << endl;
}
int main() {
  memset(cnt, 0, sizeof(cnt));
  memset(tree, 0, sizeof(tree));
  int n;
  cin >> n;
  add(0);
  while (n--) {
    char s[2];
    int num;
    scanf("%s%d", s, &num);
    switch (s[0]) {
      case '+':
        add(num);
        break;
      case '-':
        sub(num);
        break;
      case '?':
        query(num);
        break;
      default:
        break;
    }
  }
  return 0;
}

```