Description

一棵树有$n$个点，$n-1$条边，所有边长都为$1$，给出一个距离$k$，查询有多少对节点之间的距离不超过$k$。

Description

Give a tree with n vertices,each edge has a length(positive integer less than 1001).

Define dist(u,v)=The min distance between node u and v.

Give an integer k,for every pair (u,v) of vertices is called valid if and only if dist(u,v) not exceed k.

Write a program that will count how many pairs which are valid for a given tree.

Input

The input contains several test cases. The first line of each test case contains two integers n, k. (n<=10000) The following n-1 lines each contains three integers u,v,l, which means there is an edge between node u and v of length l.

The last test case is followed by two zeros.

Output

For each test case output the answer on a single line.

输入数据 1

5 4
1 2 3
1 3 1
1 4 2
3 5 1
0 0

Copy

输出数据 1

8

Copy

Source

LouTiancheng@POJ