#include <bits/stdc++.h>
using namespace std;
int n, i, j, tree[6000001][2], num, tnum[6000001];
char t1[1];
void insert(int x) {
  int s = 0;
  for (int i = 30; i >= 0; i--) {
    int c = 1 & (x >> i);
    if (!tree[s][c]) tree[s][c] = ++num;
    s = tree[s][c];
    tnum[s]++;
  }
}
void Del(int x) {
  int s = 0;
  for (int i = 30; i >= 0; i--) {
    int c = 1 & (x >> i);
    s = tree[s][c];
    tnum[s]--;
  }
}
int query(int x) {
  int s = 0, ans = 0;
  for (int i = 30; i >= 0; i--) {
    int c = (1 & (x >> i)) ^ 1;
    if (tree[s][c] && tnum[tree[s][c]]) {
      ans += 1 << i;
      s = tree[s][c];
    } else
      s = tree[s][c ^ 1];
  }
  return ans;
}
int main() {
  scanf("%d", &n);
  insert(0);
  for (i = 1; i <= n; i++) {
    int t2;
    scanf("%s%d", t1, &t2);
    if (t1[0] == '+') insert(t2);
    if (t1[0] == '-') Del(t2);
    if (t1[0] == '?') printf("%d\n", query(t2));
  }
}

### Prompt

Develop a solution in CPP to the problem described below:

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;
int n, i, j, tree[6000001][2], num, tnum[6000001];
char t1[1];
void insert(int x) {
  int s = 0;
  for (int i = 30; i >= 0; i--) {
    int c = 1 & (x >> i);
    if (!tree[s][c]) tree[s][c] = ++num;
    s = tree[s][c];
    tnum[s]++;
  }
}
void Del(int x) {
  int s = 0;
  for (int i = 30; i >= 0; i--) {
    int c = 1 & (x >> i);
    s = tree[s][c];
    tnum[s]--;
  }
}
int query(int x) {
  int s = 0, ans = 0;
  for (int i = 30; i >= 0; i--) {
    int c = (1 & (x >> i)) ^ 1;
    if (tree[s][c] && tnum[tree[s][c]]) {
      ans += 1 << i;
      s = tree[s][c];
    } else
      s = tree[s][c ^ 1];
  }
  return ans;
}
int main() {
  scanf("%d", &n);
  insert(0);
  for (i = 1; i <= n; i++) {
    int t2;
    scanf("%s%d", t1, &t2);
    if (t1[0] == '+') insert(t2);
    if (t1[0] == '-') Del(t2);
    if (t1[0] == '?') printf("%d\n", query(t2));
  }
}

```