#include <bits/stdc++.h>
using namespace std;
long long trie[6200000][2], mark[6200000][2], sz = 0;
vector<long long> bin;
void insrt(string s) {
  long long v = 0;
  for (long long i = 0; i < s.size(); ++i) {
    long long c = s[i] - '0';
    if (trie[v][c] == -1) trie[v][c] = ++sz;
    mark[v][c]++;
    v = trie[v][c];
  }
}
void dlt(string s) {
  long long v = 0;
  for (long long i = 0; i < s.size(); ++i) {
    long long c = s[i] - '0';
    mark[v][c]--;
    v = trie[v][c];
  }
}
void srch(string s) {
  long long v = 0;
  for (long long i = 0; i < s.size(); ++i) {
    long long c = s[i] - '0';
    if (trie[v][c] == -1 || mark[v][c] < 1) c ^= 1;
    bin.push_back(c);
    v = trie[v][c];
  }
}
long long dec() {
  long long val = 1, sum = 0;
  for (long long i = bin.size() - 1; i >= 0; --i) {
    if (bin[i] == 1) sum += val;
    val *= 2;
  }
  return sum;
}
void clr() {
  memset(trie, -1, sizeof(trie));
  memset(mark, 0, sizeof(mark));
  sz = 0;
}
int main() {
  long long q, n;
  char ch;
  cin >> q;
  clr();
  string s;
  s = bitset<31>(0).to_string();
  insrt(s);
  while (q--) {
    cin >> ch >> n;
    s = bitset<31>(n).to_string();
    if (ch == '+') insrt(s);
    if (ch == '-') dlt(s);
    if (ch == '?') {
      long long xr = n ^ 1073741823;
      string ss = bitset<31>(xr).to_string();
      srch(ss);
      long long val = dec();
      bin.clear();
      val ^= n;
      cout << val << endl;
    }
  }
}

### Prompt

Your task is to create 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;
long long trie[6200000][2], mark[6200000][2], sz = 0;
vector<long long> bin;
void insrt(string s) {
  long long v = 0;
  for (long long i = 0; i < s.size(); ++i) {
    long long c = s[i] - '0';
    if (trie[v][c] == -1) trie[v][c] = ++sz;
    mark[v][c]++;
    v = trie[v][c];
  }
}
void dlt(string s) {
  long long v = 0;
  for (long long i = 0; i < s.size(); ++i) {
    long long c = s[i] - '0';
    mark[v][c]--;
    v = trie[v][c];
  }
}
void srch(string s) {
  long long v = 0;
  for (long long i = 0; i < s.size(); ++i) {
    long long c = s[i] - '0';
    if (trie[v][c] == -1 || mark[v][c] < 1) c ^= 1;
    bin.push_back(c);
    v = trie[v][c];
  }
}
long long dec() {
  long long val = 1, sum = 0;
  for (long long i = bin.size() - 1; i >= 0; --i) {
    if (bin[i] == 1) sum += val;
    val *= 2;
  }
  return sum;
}
void clr() {
  memset(trie, -1, sizeof(trie));
  memset(mark, 0, sizeof(mark));
  sz = 0;
}
int main() {
  long long q, n;
  char ch;
  cin >> q;
  clr();
  string s;
  s = bitset<31>(0).to_string();
  insrt(s);
  while (q--) {
    cin >> ch >> n;
    s = bitset<31>(n).to_string();
    if (ch == '+') insrt(s);
    if (ch == '-') dlt(s);
    if (ch == '?') {
      long long xr = n ^ 1073741823;
      string ss = bitset<31>(xr).to_string();
      srch(ss);
      long long val = dec();
      bin.clear();
      val ^= n;
      cout << val << endl;
    }
  }
}

```