Bob wants to know about his ancestors, therefore, he draws a graph of his family. In that graph, root is the eldest-known family member. The leaf node is a member who has no children.
You are given a \(Q\) query and \(N\) family members. They have to just print the \(k^{th}\) ancestors with respect to that query. A member can have only one parent.
Note: Print -1 if the query is incorrect, that is, if the \(k^{th}\) ancestor is not available. The root of the tree is 1.
Input format
- The first line contains two space-separated integers \(N\) and \(Q\) denoting the number of nodes and the number of queries.
- Next \(N- 1\) lines contain two space-separated integers \(u\) and \(v\) denoting an edge between node \(u\) and node \(v\).
- Next \(Q\) lines contain two space-separated integers \(u\) and \(k\).
Output format
For each query, print a single line containing one integer.
Constraints
6 5 1 2 2 3 3 4 2 5 1 6 4 1 4 3 6 1 5 1 5 3
3 1 1 2 -1
In this tree 1st Parent of 4th node is 3 and also 3rd parent is node 1.
For Third Query 1st parent of 6 is root node.
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