#include <bits/stdc++.h>
const char nl = '\n';
using namespace std;
using ll = long long;
using ld = long double;
const int L = 30, N = 1 << L, Q = 2e5 + 10;
struct node {
  int c[2], cnt;
  node() : cnt(0) { memset(c, 0, sizeof c); }
};
node ns[(L + 1) * Q];
int ncnt = 1;
void upd(int x, int v, int i = 1, int bit = L - 1) {
  ns[i].cnt += v;
  if (bit < 0) return;
  int& c = ns[i].c[(x >> bit) & 1];
  if (!c) c = ++ncnt;
  upd(x, v, c, bit - 1);
}
int query(int x, int i = 1, int bit = L - 1) {
  if (bit < 0) return 0;
  int c = ns[i].c[!((x >> bit) & 1)];
  if (ns[c].cnt)
    return query(x, ns[i].c[!((x >> bit) & 1)], bit - 1) ^ (1 << bit);
  return query(x, ns[i].c[(x >> bit) & 1], bit - 1);
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  upd(0, 1);
  int q;
  cin >> q;
  while (q--) {
    char c;
    int x;
    cin >> c >> x;
    if (c == '+') upd(x, 1);
    if (c == '-') upd(x, -1);
    if (c == '?') cout << query(x) << nl;
  }
}

### Prompt

Your challenge is to write 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>
const char nl = '\n';
using namespace std;
using ll = long long;
using ld = long double;
const int L = 30, N = 1 << L, Q = 2e5 + 10;
struct node {
  int c[2], cnt;
  node() : cnt(0) { memset(c, 0, sizeof c); }
};
node ns[(L + 1) * Q];
int ncnt = 1;
void upd(int x, int v, int i = 1, int bit = L - 1) {
  ns[i].cnt += v;
  if (bit < 0) return;
  int& c = ns[i].c[(x >> bit) & 1];
  if (!c) c = ++ncnt;
  upd(x, v, c, bit - 1);
}
int query(int x, int i = 1, int bit = L - 1) {
  if (bit < 0) return 0;
  int c = ns[i].c[!((x >> bit) & 1)];
  if (ns[c].cnt)
    return query(x, ns[i].c[!((x >> bit) & 1)], bit - 1) ^ (1 << bit);
  return query(x, ns[i].c[(x >> bit) & 1], bit - 1);
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  upd(0, 1);
  int q;
  cin >> q;
  while (q--) {
    char c;
    int x;
    cin >> c >> x;
    if (c == '+') upd(x, 1);
    if (c == '-') upd(x, -1);
    if (c == '?') cout << query(x) << nl;
  }
}

```