---
category_name: medium
problem_code: MOSTDIST
problem_name: 'Most Distant Points'
languages_supported:
- ADA
- ASM
- BASH
- BF
- C
- 'C99 strict'
- CAML
- CLOJ
- CLPS
- 'CPP 4.3.2'
- 'CPP 4.9.2'
- CPP14
- CS2
- D
- ERL
- FORT
- FS
- GO
- HASK
- ICK
- ICON
- JAVA
- JS
- 'LISP clisp'
- 'LISP sbcl'
- LUA
- NEM
- NICE
- NODEJS
- 'PAS fpc'
- 'PAS gpc'
- PERL
- PERL6
- PHP
- PIKE
- PRLG
- PYTH
- 'PYTH 3.4'
- RUBY
- SCALA
- 'SCM guile'
- 'SCM qobi'
- ST
- TCL
- TEXT
- WSPC
max_timelimit: '1.5'
source_sizelimit: '50000'
problem_author: kostya_by
problem_tester: null
date_added: 24-10-2014
tags:
- cook52
- easy
- geometry
- heap
- kostya_by
- manhattan
editorial_url: 'http://discuss.codechef.com/problems/MOSTDIST'
time:
view_start_date: 1416768043
submit_start_date: 1416768043
visible_start_date: 1416767794
end_date: 1735669800
current: 1493557807
layout: problem
---
All submissions for this problem are available.### Read problems statements in [Mandarin Chinese](http://www.codechef.com/download/translated/COOK52/mandarin/MOSTDIST.pdf) and [Russian](http://www.codechef.com/download/translated/COOK52/russian/MOSTDIST.pdf) as well.
Let's consider a set of points **S**. Initially, **S** is an empty set. Your task is to implement a data structure that can process the following queries efficiently:
- "+ **X** **Y**" - add a new point **P** with coordinates (**X**, **Y**) to **S**. It's guaranteed that this point will not be in **S**.
- "- **N**" - remove a point that was added during the **N**'th adding query from **S**. All of the adding queries are numbered in the order of their appearance starting from 1 (queries of other types are not included). It's guaranteed that this point is in **S**.
- "? **X** **Y**" - calculate the maximal Manhattan distance between a point **P** with coordinates (**X**, **Y**) and any point from **S**. It's guaranteed that **S** will not be empty.
In addition, you won't be given the exact query data, but instead should decode it in the following way:
Let's store the result of the last processed query of the third type in a variable called **ANSWER**. Initially, **ANSWER** is equal to 0. You will be given **X'**, **Y'** and **N'** instead of the real values of **X**, **Y** and **N**. To get the real data you should perform the following computations:
- **X** = **X'** xor **ANSWER**;
- **Y** = **Y'** xor **ANSWER**;
- **N** = **N'** xor **ANSWER**.
Don't forget to update the value of **ANSWER** after processing each query of the third type.
### Note
Maybe some of you aren't familiar with some terms in the statement. Here are some articles that could help you understand the problem correctly:
- XOR operation: [http://en.wikipedia.org/wiki/Exclusive\_or](http://en.wikipedia.org/wiki/Exclusive_or)
- Manhattan distance: [http://en.wikipedia.org/wiki/Taxicab\_geometry](http://en.wikipedia.org/wiki/Taxicab_geometry)
### Input
The first line of the input contains one integer **Q** denoting the number of queries to process.
Each of the next **Q** lines contains a query to process in the format described above.
### Output
For each query on the third type you should output your answer on a new line.
### Constraints
1 ≤ **Q** ≤ 500,000(5 × 105);
0 ≤ **X'**, **Y'**, **N'** < 231 for each query;
0 ≤ **X**, **Y** ≤ 109 for each query.
### Example
<pre><b>Input:</b>
10
+ 8 1
- 1
+ 3 9
? 8 4
? 8 8
? 12 0
+ 6 5
? 7 8
? 4 5
- 9
<b>Output:</b>
10
8
2
4
11
</pre>### Explanations
Here's a non-encrypted version of the example:
<pre>
10
+ 8 1
- 1
+ 3 9
? 8 4
? 2 2
? 4 8
+ 4 7
? 5 10
? 0 1
- 2
</pre>The answers are the same.