#include <bits/stdc++.h>
using namespace std;
const int maxn = 3000005;
int sle[maxn][2], brojac, q;
int breza[maxn];
void dodaj(int x) {
  int tren = 0;
  int bt = (1 << 30);
  while (bt) {
    int ima = 0;
    if (x & bt) ima = 1;
    if (!sle[tren][ima]) sle[tren][ima] = ++brojac;
    tren = sle[tren][ima];
    breza[tren]++;
    bt >>= 1;
  }
}
void brisi(int x) {
  int tren = 0;
  int bt = (1 << 30);
  while (bt) {
    int ima = 0;
    if (x & bt) ima = 1;
    tren = sle[tren][ima];
    breza[tren]--;
    bt >>= 1;
  }
}
int query(int x) {
  int tren = 0, rez = 0;
  int bt = (1 << 30);
  while (bt) {
    int ima = 0;
    if (x & bt) ima = 1;
    int a = sle[tren][!ima];
    int b = sle[tren][ima];
    if (breza[a]) {
      rez += (1 - ima) * bt;
      tren = a;
    } else {
      rez += ima * bt;
      tren = b;
    }
    bt >>= 1;
  }
  return rez;
}
int main() {
  ios::sync_with_stdio(NULL);
  cin.tie(0);
  cout.tie(0);
  cin >> q;
  while (q--) {
    int x;
    char ch;
    cin >> ch >> x;
    if (ch == '+') dodaj(x);
    if (ch == '-') brisi(x);
    if (ch == '?') cout << max(x, x ^ query(x)) << endl;
  }
  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 int maxn = 3000005;
int sle[maxn][2], brojac, q;
int breza[maxn];
void dodaj(int x) {
  int tren = 0;
  int bt = (1 << 30);
  while (bt) {
    int ima = 0;
    if (x & bt) ima = 1;
    if (!sle[tren][ima]) sle[tren][ima] = ++brojac;
    tren = sle[tren][ima];
    breza[tren]++;
    bt >>= 1;
  }
}
void brisi(int x) {
  int tren = 0;
  int bt = (1 << 30);
  while (bt) {
    int ima = 0;
    if (x & bt) ima = 1;
    tren = sle[tren][ima];
    breza[tren]--;
    bt >>= 1;
  }
}
int query(int x) {
  int tren = 0, rez = 0;
  int bt = (1 << 30);
  while (bt) {
    int ima = 0;
    if (x & bt) ima = 1;
    int a = sle[tren][!ima];
    int b = sle[tren][ima];
    if (breza[a]) {
      rez += (1 - ima) * bt;
      tren = a;
    } else {
      rez += ima * bt;
      tren = b;
    }
    bt >>= 1;
  }
  return rez;
}
int main() {
  ios::sync_with_stdio(NULL);
  cin.tie(0);
  cout.tie(0);
  cin >> q;
  while (q--) {
    int x;
    char ch;
    cin >> ch >> x;
    if (ch == '+') dodaj(x);
    if (ch == '-') brisi(x);
    if (ch == '?') cout << max(x, x ^ query(x)) << endl;
  }
  return 0;
}

```