#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 10;
int n, tot, root;
int tr[N * 30][2];
pair<int, long long> End[N * 30];
void change(pair<int, long long> &X, int v, long long x) {
  int V = X.first + v;
  X = {V, x};
}
void Insert(int &p, long long x, int de, int v) {
  if (!p) p = ++tot;
  if (de < 0) return change(End[p], v, x), void();
  int ne = (x >> de) & 1;
  Insert(tr[p][ne], x, de - 1, v);
}
pair<int, long long> dfs(int p, long long x, int de) {
  if (p == 0) return pair<int, long long>{-1, 0};
  if (de < 0) return End[p];
  int ne = (x >> de) & 1;
  pair<int, long long> Max;
  Max = {-1, 0};
  Max = max(Max, dfs(tr[p][ne ^ 1], x, de - 1));
  if (Max.first > 0) return Max;
  return dfs(tr[p][ne], x, de - 1);
}
int main() {
  scanf("%d", &n);
  Insert(root, 0, 30, 1);
  while (n--) {
    char ch;
    long long x;
    ch = getchar();
    while (ch != '+' && ch != '-' && ch != '?') ch = getchar();
    scanf("%lld", &x);
    if (ch == '+') Insert(root, x, 30, 1);
    if (ch == '-') Insert(root, x, 30, -1);
    if (ch == '?') printf("%lld\n", dfs(root, x, 30).second ^ x);
  }
  return 0;
}

### Prompt

Please create a solution in cpp 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 N = 2e5 + 10;
int n, tot, root;
int tr[N * 30][2];
pair<int, long long> End[N * 30];
void change(pair<int, long long> &X, int v, long long x) {
  int V = X.first + v;
  X = {V, x};
}
void Insert(int &p, long long x, int de, int v) {
  if (!p) p = ++tot;
  if (de < 0) return change(End[p], v, x), void();
  int ne = (x >> de) & 1;
  Insert(tr[p][ne], x, de - 1, v);
}
pair<int, long long> dfs(int p, long long x, int de) {
  if (p == 0) return pair<int, long long>{-1, 0};
  if (de < 0) return End[p];
  int ne = (x >> de) & 1;
  pair<int, long long> Max;
  Max = {-1, 0};
  Max = max(Max, dfs(tr[p][ne ^ 1], x, de - 1));
  if (Max.first > 0) return Max;
  return dfs(tr[p][ne], x, de - 1);
}
int main() {
  scanf("%d", &n);
  Insert(root, 0, 30, 1);
  while (n--) {
    char ch;
    long long x;
    ch = getchar();
    while (ch != '+' && ch != '-' && ch != '?') ch = getchar();
    scanf("%lld", &x);
    if (ch == '+') Insert(root, x, 30, 1);
    if (ch == '-') Insert(root, x, 30, -1);
    if (ch == '?') printf("%lld\n", dfs(root, x, 30).second ^ x);
  }
  return 0;
}

```