human
Write me a Python code to print one integer — the maximum value of bitwise exclusive OR (XOR) of integer xi and some integer from the multiset A given the following:
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 , 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  — maximum among integers , , ,  and .
The above is tricky. Write me a correct solution in PYTHON3.
assistant
#Here is Python code to print one integer — the maximum value of bitwise exclusive OR (XOR) of integer xi and some integer from the multiset A.

class Node:
  def __init__(self, value):
    self.parent = None
    self.val = value
    self.zero = None
    self.one = None
    self.marker = 0
    self.max_len = 0
    
root = Node(-1)

def add(n):
  #print("Add", n)
  
  curr_node = root
  bitstr = bin(n)[2:].zfill(32)   # 32-bit string

  for bit in bitstr:
    if bit == "1":
      if curr_node.one == None:
        curr_node.one = Node(1)
        curr_node.one.parent = curr_node
      curr_node = curr_node.one
    else:
      if curr_node.zero == None:
        curr_node.zero = Node(0)
        curr_node.zero.parent = curr_node
      curr_node = curr_node.zero
      
  curr_node.marker += 1
  
def remove(n):
  #print("Remove", n)
  
  curr_node = root
  bitstr = bin(n)[2:].zfill(32)
  for bit in bitstr:
    if bit == "1":
      curr_node = curr_node.one
    else:
      curr_node = curr_node.zero

  curr_node.marker -= 1
  if curr_node.marker == 0:
    while curr_node.parent != None:
      if curr_node.one is None and curr_node.zero is None:
        if curr_node.val == 1:
          curr_node.parent.one = None
        else:
          curr_node.parent.zero = None
      curr_node = curr_node.parent
        
  
def query(n):
  #print("Query", n)
  
  bitstr = bin(n)[2:].zfill(32)
  curr_node = root
  result = []
  
  for bit in bitstr:
    
    b = int(bit)
    looking_for = 1-b
    
    zero_present = curr_node.zero != None
    one_present = curr_node.one != None
    
    if looking_for == 0 and zero_present:
      curr_node = curr_node.zero
      result.append("1")
      
    elif looking_for == 1 and one_present:
      curr_node = curr_node.one
      result.append("1")
      
    elif looking_for == 0 and one_present:
      curr_node = curr_node.one
      result.append("0")
    else:
      curr_node = curr_node.zero
      result.append("0")
      
  print(int("".join(result), 2))
  
# Parse input
num_q = int(input())
for _ in range(num_q):
  
  expr = input()
  symbol = expr[0]
  num = int(expr[2:])
  
  add(0)    # 0 is always in the set
  
  if symbol ==...