#include <bits/stdc++.h>
using namespace std;
const int MAXN = (int)2e5 + 7;
const int INF = (int)1e9 + 7;
const long long LINF = (long long)1e12 + 7;
const int MOD = (int)1e9 + 7;
void file() {}
inline int readChar();
template <class T = int>
inline T readInt();
template <class Tl = long long>
inline Tl readLong();
template <class T>
inline void writeInt(T x, char end = 0);
template <class Tl>
inline void writeLong(Tl x, char end = 0);
inline void writeChar(int x);
inline void writeWord(const char *s);
static const int buf_size = 4096;
inline int getChar() {
  static char buf[buf_size];
  static int len = 0, pos = 0;
  if (pos == len) pos = 0, len = fread(buf, 1, buf_size, stdin);
  if (pos == len) return -1;
  return buf[pos++];
}
inline int readChar() {
  int c = getChar();
  while (c <= 32) c = getChar();
  return c;
}
template <class T>
inline T readInt() {
  int s = 1, c = readChar();
  T x = 0;
  if (c == '-') s = -1, c = getChar();
  while ('0' <= c && c <= '9') x = x * 10 + c - '0', c = getChar();
  return s == 1 ? x : -x;
}
template <class Tl>
inline Tl readLong() {
  int s = 1, c = readChar();
  Tl x = 0;
  if (c == '-') s = -1, c = getChar();
  while ('0' <= c && c <= '9') x = x * 10 + c - '0', c = getChar();
  return s == 1 ? x : -x;
}
static int write_pos = 0;
static char write_buf[buf_size];
inline void writeChar(int x) {
  if (write_pos == buf_size)
    fwrite(write_buf, 1, buf_size, stdout), write_pos = 0;
  write_buf[write_pos++] = x;
}
template <class T>
inline void writeInt(T x, char end) {
  if (x < 0) writeChar('-'), x = -x;
  char s[24];
  int n = 0;
  while (x || !n) s[n++] = '0' + x % 10, x /= 10;
  while (n--) writeChar(s[n]);
  if (end) writeChar(end);
}
template <class Tl>
inline void writeLong(Tl x, char end) {
  if (x < 0) writeChar('-'), x = -x;
  char s[24];
  int n = 0;
  while (x || !n) s[n++] = '0' + x % 10, x /= 10;
  while (n--) writeChar(s[n]);
  if (end) writeChar(end);
}
inline void writeWord(const char *s) {
  while (*s) writeChar(*s++);
}
struct Flusher {
  ~Flusher() {
    if (write_pos) fwrite(write_buf, 1, write_pos, stdout), write_pos = 0;
  }
} flusher;
vector<vector<int> > G;
vector<pair<int, int> > p;
vector<int> coun;
void insert(int x) {
  int v = 0;
  for (int i = 30; i >= 0; --i) {
    ++coun[v];
    if (G[v][(x >> i) & 1] == -1) {
      G.push_back(vector<int>(2, -1));
      coun.push_back(0);
      p.push_back({v, (x >> i) & 1});
      G[v][(x >> i) & 1] = G.size() - 1;
    }
    v = G[v][(x >> i) & 1];
  }
  ++coun[v];
}
void erase(int x) {
  int v = 0;
  for (int i = 30; i >= 0; --i) {
    --coun[v];
    v = G[v][(x >> i) & 1];
  }
  --coun[v];
  while (p[v].first != -1 && !coun[v]) {
    G[p[v].first][p[v].second] = -1;
    v = p[v].first;
  }
}
int get(int x) {
  int ans = 0, v = 0;
  for (int i = 30; i >= 0; --i) {
    if (G[v][(x >> i) & 1] != -1) {
      if ((x >> i) & 1) {
        ans += (1 << i);
      }
      v = G[v][(x >> i) & 1];
    } else {
      if (!((x >> i) & 1)) {
        ans += (1 << i);
      }
      v = G[v][!((x >> i) & 1)];
    }
  }
  return ans;
}
int main() {
  file();
  int q = readInt();
  G.push_back(vector<int>(2, -1));
  coun.push_back(0);
  p.push_back({-1, 0});
  insert(0);
  while (q--) {
    char c = readChar();
    int x = readInt();
    if (c == '+') {
      insert(x);
    }
    if (c == '-') {
      erase(x);
    }
    if (c == '?') {
      int cur = x ^ ((1ll << 31) - 1);
      int ans = get(cur) ^ x;
      writeInt(ans, '\n');
    }
  }
  return 0;
}

### 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;
const int MAXN = (int)2e5 + 7;
const int INF = (int)1e9 + 7;
const long long LINF = (long long)1e12 + 7;
const int MOD = (int)1e9 + 7;
void file() {}
inline int readChar();
template <class T = int>
inline T readInt();
template <class Tl = long long>
inline Tl readLong();
template <class T>
inline void writeInt(T x, char end = 0);
template <class Tl>
inline void writeLong(Tl x, char end = 0);
inline void writeChar(int x);
inline void writeWord(const char *s);
static const int buf_size = 4096;
inline int getChar() {
  static char buf[buf_size];
  static int len = 0, pos = 0;
  if (pos == len) pos = 0, len = fread(buf, 1, buf_size, stdin);
  if (pos == len) return -1;
  return buf[pos++];
}
inline int readChar() {
  int c = getChar();
  while (c <= 32) c = getChar();
  return c;
}
template <class T>
inline T readInt() {
  int s = 1, c = readChar();
  T x = 0;
  if (c == '-') s = -1, c = getChar();
  while ('0' <= c && c <= '9') x = x * 10 + c - '0', c = getChar();
  return s == 1 ? x : -x;
}
template <class Tl>
inline Tl readLong() {
  int s = 1, c = readChar();
  Tl x = 0;
  if (c == '-') s = -1, c = getChar();
  while ('0' <= c && c <= '9') x = x * 10 + c - '0', c = getChar();
  return s == 1 ? x : -x;
}
static int write_pos = 0;
static char write_buf[buf_size];
inline void writeChar(int x) {
  if (write_pos == buf_size)
    fwrite(write_buf, 1, buf_size, stdout), write_pos = 0;
  write_buf[write_pos++] = x;
}
template <class T>
inline void writeInt(T x, char end) {
  if (x < 0) writeChar('-'), x = -x;
  char s[24];
  int n = 0;
  while (x || !n) s[n++] = '0' + x % 10, x /= 10;
  while (n--) writeChar(s[n]);
  if (end) writeChar(end);
}
template <class Tl>
inline void writeLong(Tl x, char end) {
  if (x < 0) writeChar('-'), x = -x;
  char s[24];
  int n = 0;
  while (x || !n) s[n++] = '0' + x % 10, x /= 10;
  while (n--) writeChar(s[n]);
  if (end) writeChar(end);
}
inline void writeWord(const char *s) {
  while (*s) writeChar(*s++);
}
struct Flusher {
  ~Flusher() {
    if (write_pos) fwrite(write_buf, 1, write_pos, stdout), write_pos = 0;
  }
} flusher;
vector<vector<int> > G;
vector<pair<int, int> > p;
vector<int> coun;
void insert(int x) {
  int v = 0;
  for (int i = 30; i >= 0; --i) {
    ++coun[v];
    if (G[v][(x >> i) & 1] == -1) {
      G.push_back(vector<int>(2, -1));
      coun.push_back(0);
      p.push_back({v, (x >> i) & 1});
      G[v][(x >> i) & 1] = G.size() - 1;
    }
    v = G[v][(x >> i) & 1];
  }
  ++coun[v];
}
void erase(int x) {
  int v = 0;
  for (int i = 30; i >= 0; --i) {
    --coun[v];
    v = G[v][(x >> i) & 1];
  }
  --coun[v];
  while (p[v].first != -1 && !coun[v]) {
    G[p[v].first][p[v].second] = -1;
    v = p[v].first;
  }
}
int get(int x) {
  int ans = 0, v = 0;
  for (int i = 30; i >= 0; --i) {
    if (G[v][(x >> i) & 1] != -1) {
      if ((x >> i) & 1) {
        ans += (1 << i);
      }
      v = G[v][(x >> i) & 1];
    } else {
      if (!((x >> i) & 1)) {
        ans += (1 << i);
      }
      v = G[v][!((x >> i) & 1)];
    }
  }
  return ans;
}
int main() {
  file();
  int q = readInt();
  G.push_back(vector<int>(2, -1));
  coun.push_back(0);
  p.push_back({-1, 0});
  insert(0);
  while (q--) {
    char c = readChar();
    int x = readInt();
    if (c == '+') {
      insert(x);
    }
    if (c == '-') {
      erase(x);
    }
    if (c == '?') {
      int cur = x ^ ((1ll << 31) - 1);
      int ans = get(cur) ^ x;
      writeInt(ans, '\n');
    }
  }
  return 0;
}

```