#5672. CSES1688 公司查询 II
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CSES1688 公司查询 II
Company Queries II
A company has n employees, who form a tree hierarchy where each employee has a boss, except for the general director. Your task is to process q queries of the form: who is the lowest common boss of employees a and b in the hierarchy?
Input
The first input line has two integers n and q: the number of employees and queries. The employees are numbered 1,2,\dots,n, and employee 1 is the general director. The next line has n-1 integers e_2,e_3,\dots,e_n: for each employee 2,3,\dots,n their boss. Finally, there are q lines describing the queries. Each line has two integers a and b: who is the lowest common boss of employees a and b?
Output
Print the answer for each query.
Constraints
Example
Input
5 3
1 1 3 3
4 5
2 5
1 4
Output
3
1
1