#include <bits/stdc++.h>
using namespace std;
const int inf = 0x3f3f3f3f;
const double eps = 1e-6;
const int mod = 1e9 + 7;
const int maxn = 1010;
int q;
multiset<int> st;
inline bool yes(int x, int pos) {
  auto p = st.lower_bound(x);
  if (p == st.end()) return 0;
  if (*p >= (x + (1 << pos))) return 0;
  return 1;
}
int main() {
  scanf("%d", &q);
  st.insert(0);
  while (q--) {
    char ch;
    int a;
    scanf(" %c%d", &ch, &a);
    if (ch == '+') {
      st.insert(a);
    } else if (ch == '-') {
      st.erase(st.find(a));
    } else {
      int mn = 0;
      int t = 0;
      for (int i = 30; i >= 0; i--) {
        if ((a & (1 << i)) == 0) {
          t ^= (1 << i);
          if (!yes(t, i)) t ^= (1 << i);
        } else {
          if (!yes(t, i)) t ^= (1 << i);
        }
      }
      printf("%d\n", a ^ t);
    }
  }
}

### Prompt

Generate 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;
const double eps = 1e-6;
const int mod = 1e9 + 7;
const int maxn = 1010;
int q;
multiset<int> st;
inline bool yes(int x, int pos) {
  auto p = st.lower_bound(x);
  if (p == st.end()) return 0;
  if (*p >= (x + (1 << pos))) return 0;
  return 1;
}
int main() {
  scanf("%d", &q);
  st.insert(0);
  while (q--) {
    char ch;
    int a;
    scanf(" %c%d", &ch, &a);
    if (ch == '+') {
      st.insert(a);
    } else if (ch == '-') {
      st.erase(st.find(a));
    } else {
      int mn = 0;
      int t = 0;
      for (int i = 30; i >= 0; i--) {
        if ((a & (1 << i)) == 0) {
          t ^= (1 << i);
          if (!yes(t, i)) t ^= (1 << i);
        } else {
          if (!yes(t, i)) t ^= (1 << i);
        }
      }
      printf("%d\n", a ^ t);
    }
  }
}

```