You are given a tree with N nodes. The tree nodes are numbered from 1 to N. Each node has an integer weight.
We will ask you to perform the following operation:

• u v : ask for how many different integers that represent the weight of nodes there are on the path from u to v.

• 给定 n 个结点的树，每个结点有一种颜色。
• m 次询问，每次询问给出  u,v，回答 u,v 之间的路径上的结点的不同颜色数。
• 1≤n≤4×10⁴，1≤m≤10⁵，颜色是不超过 2×10⁹ 的非负整数。

In the first line there are two integers N and M. (N <= 40000, M <= 100000)

In the second line there are N integers. The i-th integer denotes the weight of the i-th node.

In the next N-1 lines, each line contains two integers u v, which describes an edge (u, v).

In the next M lines, each line contains two integers u v, which means an operation asking for how many different integers that represent the weight of nodes there are on the path from u to v.

For each operation, print its result.

莫队 DFS