#P6540. Neko and tree

    ID: 5397 远端评测题 1000ms 512MiB 尝试: 0 已通过: 0 难度: (无) 上传者: 标签>2019CCPC湖南全国邀请赛(广东省赛、江苏省赛)重现赛

Neko and tree

Problem Description

Neko has a tree with $n$ nodes.
There are $m$ key nodes on tree. Neko want to you to selecte some key nodes satisfying the distance between any two selected nodes less than or equal to $k$.
Neko thinks this work is too easy,so Neko want to know how many different way for selecting nodes.
Calculate the answer after mod $10^9+7$.
Note that you have to select at least one key node.

Input

The first line contains three integers $n, m, k(1 \leq n,m,k \leq 5000)$.
The next $n-1$ line, each line contains two integers $u, v$,indicating there is an edge connecting node $u$ and node $v$.
The last line contains $m$ integers, indicating key node.

Output

Output the number of way for selecting nodes.

4 3 2 1 2 1 3 2 4 2 3 1
7