Problem7625--[CSES Problem Set] Distance Queries

7625: [CSES Problem Set] Distance Queries

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Time Limit : 2.000 sec  Memory Limit : 256 MiB

Description

You are given a tree consisting of $n$ nodes.
Your task is to process $q$ queries of the form: what is the distance between nodes $a$ and $b$?

Input

The first input line contains two integers $n$ and $q$: the number of nodes and queries. The nodes are numbered $1,2,\ldots,n$.
Then there are $n-1$ lines describing the edges. Each line contains two integers $a$ and $b$: there is an edge between nodes $a$ and $b$.
Finally, there are $q$ lines describing the queries. Each line contains two integer $a$ and $b$: what is the distance between nodes $a$ and $b$?

Output

Print $q$ integers: the answer to each query.

Constraints

$1≤n,q≤2⋅10^5$
$1 \le a,b \le n$

Sample 1 Input

5 3
1 2
1 3
3 4
3 5
1 3
2 5
1 4

Sample 1 Output

1
3
2

HINT

相同题目:CSES 1135

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