---
category_name: medium
problem_code: TALCA
problem_name: 'Lowest Common Ancestor'
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: '3'
source_sizelimit: '50000'
problem_author: tuananh93
problem_tester: null
date_added: 3-07-2014
tags:
- lca
- ltime14
- medium
- tree
- tuananh93
editorial_url: 'http://discuss.codechef.com/problems/TALCA'
time:
view_start_date: 1406452500
submit_start_date: 1406452500
visible_start_date: 1406452500
end_date: 1735669800
current: 1493557942
layout: problem
---
All submissions for this problem are available.### Read problems statements in [Mandarin Chinese.](http://www.codechef.com/download/translated/LTIME14/mandarin/TALCA.pdf)
In a rooted tree, the [lowest common ancestor](http://en.wikipedia.org/wiki/Lowest_common_ancestor) (or LCA for short) of two vertices **u** and **v** is defined as the lowest vertex that is ancestor of both that two vertices.
Given a tree of **N** vertices, you need to answer the question of the form "**r u v**" which means if the root of the tree is at **r** then what is LCA of **u** and **v**.
### Input
The first line contains a single integer **N**. Each line in the next **N - 1** lines contains a pair of integer **u** and **v** representing a edge between this two vertices.
The next line contains a single integer **Q** which is the number of the queries. Each line in the next **Q** lines contains three integers **r, u, v** representing a query.
### Output
For each query, write out the answer on a single line.
### Constraints
20 points:
- 1 ≤ **N**, **Q** ≤ 100
40 points:
- 1 ≤ **N**, **Q** ≤ 105
- There is less than 10 unique value of r in all queries
40 points:
- 1 ≤ **N**, **Q** ≤ 2 × 105
### Example
<pre><b>Input:</b>
4
1 2
2 3
1 4
2
1 4 2
2 4 2
<b>Output:</b>
1
2
</pre>### Explanation
- "1 4 2": if 1 is the root, it is parent of both 2 and 4 so LCA of 2 and 4 is 1.
- "2 4 2": the root of the tree is at 2, according to the definition, LCA of any vertex with 2 is 2.