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Query on tree - MarisaOJ: Marisa Online Judge

Query on tree

Time limit: 1000 ms
Memory limit: 256 MB

You are given a weighted tree with n vertices. In this tree:

  • d(u,v) represents the weight of the minimum edge on the simple path from vertex u to vertex v.

Your task is to handle q queries of the form (u,k), count the number of vertices v for which d(u,v)=k.

Input

  • The first line contains two integers n,q.
  • The next n−1 lines, each line contains three integers u,v,w, there is an edge of weight w between u and v.
  • The next q lines, each line contains two integers u,k, a query.

Output

  • Print an integer is the answer for each query.

Constraints

  • 1≤n,q≤105.
  • 1≤u,v≤n.
  • 1≤w,k≤n.

Example

Input:

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

Output:

2
1