#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
const long double pi = acos(-1);
const ll N = 1600000;
ll bor[N * 2][2], cnt = 1;
ll temp[N * 2];
void add(ll n) {
  ll x = 0;
  for (ll bit = 30; bit > -1; bit--) {
    ll y = ((n >> bit) & 1);
    if (bor[x][y] == 0) {
      bor[x][y] = cnt;
      cnt++;
    }
    temp[x]++;
    x = bor[x][y];
  }
  temp[x]++;
}
void del(ll n) {
  ll x = 0;
  for (ll bit = 30; bit > -1; bit--) {
    ll y = ((n >> bit) & 1);
    temp[x]--;
    x = bor[x][y];
  }
  temp[x]--;
}
void XoR(ll n) {
  ll x = 0, mx = 0, bin = 1073741824;
  for (ll bit = 30; bit > -1; bit--) {
    ll y = ((n >> bit) & 1);
    if (bor[x][abs(y - 1)] != 0 and temp[bor[x][abs(y - 1)]] > 0)
      mx += bin, x = bor[x][abs(y - 1)];
    else if (bor[x][y] != 0 and temp[bor[x][y]] > 0)
      x = bor[x][y];
    else
      break;
    bin /= 2;
  }
  cout << mx << '\n';
}
int main() {
  ios_base::sync_with_stdio(0);
  cout.tie(0);
  cin.tie(0);
  ll n;
  cin >> n;
  add(0);
  for (ll i = 0; i < n; i++) {
    char d;
    ll a;
    cin >> d >> a;
    if (d == '+') add(a);
    if (d == '-') del(a);
    if (d == '?') XoR(a);
  }
  return 0;
}

### Prompt

In Cpp, your task is to solve 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;
using ll = long long;
using ld = long double;
const long double pi = acos(-1);
const ll N = 1600000;
ll bor[N * 2][2], cnt = 1;
ll temp[N * 2];
void add(ll n) {
  ll x = 0;
  for (ll bit = 30; bit > -1; bit--) {
    ll y = ((n >> bit) & 1);
    if (bor[x][y] == 0) {
      bor[x][y] = cnt;
      cnt++;
    }
    temp[x]++;
    x = bor[x][y];
  }
  temp[x]++;
}
void del(ll n) {
  ll x = 0;
  for (ll bit = 30; bit > -1; bit--) {
    ll y = ((n >> bit) & 1);
    temp[x]--;
    x = bor[x][y];
  }
  temp[x]--;
}
void XoR(ll n) {
  ll x = 0, mx = 0, bin = 1073741824;
  for (ll bit = 30; bit > -1; bit--) {
    ll y = ((n >> bit) & 1);
    if (bor[x][abs(y - 1)] != 0 and temp[bor[x][abs(y - 1)]] > 0)
      mx += bin, x = bor[x][abs(y - 1)];
    else if (bor[x][y] != 0 and temp[bor[x][y]] > 0)
      x = bor[x][y];
    else
      break;
    bin /= 2;
  }
  cout << mx << '\n';
}
int main() {
  ios_base::sync_with_stdio(0);
  cout.tie(0);
  cin.tie(0);
  ll n;
  cin >> n;
  add(0);
  for (ll i = 0; i < n; i++) {
    char d;
    ll a;
    cin >> d >> a;
    if (d == '+') add(a);
    if (d == '-') del(a);
    if (d == '?') XoR(a);
  }
  return 0;
}

```