#include <bits/stdc++.h>
using namespace std;
const int MAXN = 30 * 200100;
int q;
int t[MAXN][2];
int cnt[MAXN];
int sz = 1;
void add(int x) {
  int cur = 0;
  for (int i = 29; i > -1; --i) {
    int bit = (x >> i) & 1;
    if (t[cur][bit] == -1) {
      t[cur][bit] = sz++;
    }
    cur = t[cur][bit];
    ++cnt[cur];
  }
}
void remove(int x) {
  int cur = 0;
  for (int i = 29; i > -1; --i) {
    int bit = (x >> i) & 1;
    cur = t[cur][bit];
    --cnt[cur];
  }
}
int ask(int x) {
  int res = 0;
  int cur = 0;
  for (int i = 29; i > -1; --i) {
    int bit = (x >> i) & 1;
    if (t[cur][bit ^ 1] != -1 && cnt[t[cur][bit ^ 1]] > 0) {
      cur = t[cur][bit ^ 1];
      res |= 1 << i;
    } else {
      assert(cnt[t[cur][bit]] > 0);
      cur = t[cur][bit];
    }
  }
  return res;
}
int main() {
  scanf("%d", &q);
  memset(t, 0xff, sizeof t);
  assert(getchar() == '\n');
  add(0);
  for (int i = 0; i < q; ++i) {
    char c;
    int x;
    scanf("%c %d\n", &c, &x);
    if (c == '+') {
      add(x);
    } else if (c == '-') {
      remove(x);
    } else {
      assert(c == '?');
      printf("%d\n", ask(x));
    }
  }
  return 0;
}

### Prompt

Please formulate 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 MAXN = 30 * 200100;
int q;
int t[MAXN][2];
int cnt[MAXN];
int sz = 1;
void add(int x) {
  int cur = 0;
  for (int i = 29; i > -1; --i) {
    int bit = (x >> i) & 1;
    if (t[cur][bit] == -1) {
      t[cur][bit] = sz++;
    }
    cur = t[cur][bit];
    ++cnt[cur];
  }
}
void remove(int x) {
  int cur = 0;
  for (int i = 29; i > -1; --i) {
    int bit = (x >> i) & 1;
    cur = t[cur][bit];
    --cnt[cur];
  }
}
int ask(int x) {
  int res = 0;
  int cur = 0;
  for (int i = 29; i > -1; --i) {
    int bit = (x >> i) & 1;
    if (t[cur][bit ^ 1] != -1 && cnt[t[cur][bit ^ 1]] > 0) {
      cur = t[cur][bit ^ 1];
      res |= 1 << i;
    } else {
      assert(cnt[t[cur][bit]] > 0);
      cur = t[cur][bit];
    }
  }
  return res;
}
int main() {
  scanf("%d", &q);
  memset(t, 0xff, sizeof t);
  assert(getchar() == '\n');
  add(0);
  for (int i = 0; i < q; ++i) {
    char c;
    int x;
    scanf("%c %d\n", &c, &x);
    if (c == '+') {
      add(x);
    } else if (c == '-') {
      remove(x);
    } else {
      assert(c == '?');
      printf("%d\n", ask(x));
    }
  }
  return 0;
}

```