#include <bits/stdc++.h>
using namespace std;
const int maxn = 3000000;
int n, i, x, t, f[maxn][2], a[maxn], h[31];
char c;
inline int read() {
  int x = 0;
  char ch = getchar();
  while (ch < '0' || ch > '9') ch = getchar();
  while (ch >= '0' && ch <= '9') x = x * 10 + ch - '0', ch = getchar();
  return x;
}
void insert(int s) {
  int x = 0, y;
  for (int i = 30; i >= 0; i--) {
    y = s & h[i];
    if (y > 0) y = 1;
    if (f[x][y] == 0) f[x][y] = ++t;
    x = f[x][y];
    ++a[x];
  }
}
void del(int s) {
  int x = 0, y;
  for (int i = 30; i >= 0; i--) {
    y = s & h[i];
    if (y > 0) y = 1;
    x = f[x][y];
    --a[x];
  }
}
int find(int s) {
  int x = 0, y;
  int m = s;
  for (int i = 30; i >= 0; i--) {
    y = s & h[i];
    if (y > 0) y = 1;
    y ^= 1;
    if (a[f[x][y]] == 0) y ^= 1;
    if (y == 1) m ^= h[i];
    x = f[x][y];
  }
  return m;
}
int main() {
  n = read();
  for (i = 0; i <= 30; i++) h[i] = 1 << i;
  t = 0;
  insert(0);
  for (i = 1; i <= n; i++) {
    c = getchar();
    x = read();
    if (c == '+') insert(x);
    if (c == '-') del(x);
    if (c == '?') printf("%d\n", find(x));
  }
  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;
const int maxn = 3000000;
int n, i, x, t, f[maxn][2], a[maxn], h[31];
char c;
inline int read() {
  int x = 0;
  char ch = getchar();
  while (ch < '0' || ch > '9') ch = getchar();
  while (ch >= '0' && ch <= '9') x = x * 10 + ch - '0', ch = getchar();
  return x;
}
void insert(int s) {
  int x = 0, y;
  for (int i = 30; i >= 0; i--) {
    y = s & h[i];
    if (y > 0) y = 1;
    if (f[x][y] == 0) f[x][y] = ++t;
    x = f[x][y];
    ++a[x];
  }
}
void del(int s) {
  int x = 0, y;
  for (int i = 30; i >= 0; i--) {
    y = s & h[i];
    if (y > 0) y = 1;
    x = f[x][y];
    --a[x];
  }
}
int find(int s) {
  int x = 0, y;
  int m = s;
  for (int i = 30; i >= 0; i--) {
    y = s & h[i];
    if (y > 0) y = 1;
    y ^= 1;
    if (a[f[x][y]] == 0) y ^= 1;
    if (y == 1) m ^= h[i];
    x = f[x][y];
  }
  return m;
}
int main() {
  n = read();
  for (i = 0; i <= 30; i++) h[i] = 1 << i;
  t = 0;
  insert(0);
  for (i = 1; i <= n; i++) {
    c = getchar();
    x = read();
    if (c == '+') insert(x);
    if (c == '-') del(x);
    if (c == '?') printf("%d\n", find(x));
  }
  return 0;
}

```