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>.
def num_to_bitstring(n):
  '''converts num to bitstring of length 30'''
  b = bin(n)
  assert b[:2] == "0b"
  b = b[2:]
  return "0" * (30 - len(b)) + b
  
class Node:
  def __init__(self, val = 0):
    self.value = val #number of occurances
    self.left = None
    self.right = None
  
  def add(self):
    self.value = self.value + 1

class Trie:
  def __init__(self):
    self.head = Node(1)
    
  def add(self, s):
    current = self.head
    for b in s:
      if b == "0":
        if current.left == None:
          current.left = Node()
          current = current.left
        else:
          current = current.left
      elif b == "1":
        if current.right == None:
          current.right = Node()
          current = current.right
        else:
          current = current.right
    current.value = current.value + 1
          
  def subtract(self, s):
    current = self.head
    last_branch = None
    #have a last valid, if after going to a leaf it turns out 1 -> 0, we need to trim a branch, so take last valid set either left or right to None
    
    for b in s:
      if (current.left != None) and (current.right != None):
        if b == "0":
          last_branch = (current, "0")
        elif b == "1":
          last_branch = (current, "1")
      if b == "0":
        current = current.left
      elif b == "1":
        current = current.right
        
    current.value = current.value - 1
    if current.value == 0:
      if last_branch[1] == "0":
        last_branch[0].left = None
      elif last_branch[1] == "1":
        last_branch[0].right = None
    
  def xor(self, s):
    sum = 0
    i = 29
    current = self.head
    for b in s:
      if b == "0":
        if current.right != None:
          current = current.right
          sum += 2 ** i
        else:
          current = current.left
      else:
        if current.left != None:
          current = current.left
          sum += 2 ** i
        else:
          current = current.right
      i -= 1
    return sum
    
def main():
  t = Trie()
  s = num_to_bitstring(0)
  t.add(s)
  q = int(input())
  for a0 in range(q):
    query = input()
    s = num_to_bitstring(int(query[2:]))
    if query[0] == "+":
      t.add(s)
    elif query[0] == "-":
      t.subtract(s)
    elif query[0] == "?":
      print(t.xor(s))
      
main()
  
