Bobo has a tree with n vertices. There are m vertices on the tree that bobo thinks very special.
bobo would like to choose a (maybe empty) subset of vertices as control points, so that every special vertex can reach an control points via no more than r edges.
Find out the number of such subsets, modulo (109+7).
The first line contains 3 integers n,m,r (1≤n≤2000,0≤m≤n,0≤r<n).
Vertices are numbered by 1,2,…,n for convenience.
The second line contains m distinct integers v_1,v_2,…,v_m which denotes the special vertices (1≤v_i≤n).
Each of the following (n−1) lines contains 2 integers a_i,b_i which denotes an edge between vertices a_i and b_i (1≤a_i,b_i≤n).
A single integer denotes the number of subsets.