点分治

//POJ 1741
//by Cydiater
//2016.8.17
#include <iostream>
#include <cstring>
#include <string>
#include <algorithm>
#include <queue>
#include <map>
#include <ctime>
#include <cmath>
#include <cstdlib>
#include <iomanip>
#include <cstdio>
using namespace std;
#define ll long long
#define up(i,j,n)       for(int i=j;i<=n;i++)
#define down(i,j,n)     for(int i=j;i>=n;i--)
const int MAXN=1e5+5;
const int oo=0x3f3f3f3f;
inline int read(){
      char ch=getchar();int x=0,f=1;
      while(ch>‘9‘||ch<‘0‘){if(ch==‘-‘)f=-1;ch=getchar();}
      while(ch>=‘0‘&&ch<=‘9‘){x=x*10+ch-‘0‘;ch=getchar();}
      return x*f;
}
int N,K,LINK[MAXN],len=0,root,siz[MAXN],dis[MAXN],ms[MAXN],sum,ans,dep[MAXN],q[MAXN],head,tail;
bool vis[MAXN];
struct edge{int y,next,v;}e[MAXN];
namespace solution{
      inline void insert(int x,int y,int v){e[++len].next=LINK[x];LINK[x]=len;e[len].y=y;e[len].v=v;}
      void init(){
            if(N==0&&K==0)exit(0);
            len=0;ans=0;
            memset(LINK,0,sizeof(LINK));
            memset(siz,0,sizeof(siz));
            memset(vis,0,sizeof(vis));
            memset(dis,0,sizeof(dis));
            memset(dep,0,sizeof(dep));
            memset(ms,0,sizeof(ms));
            up(i,1,N-1){
                  int x=read(),y=read(),v=read();
                  insert(x,y,v);
                  insert(y,x,v);
            }
      }
      void getroot(int node,int fa){
            siz[node]=1;ms[node]=0;
            for(int i=LINK[node];i;i=e[i].next)
                  if(!vis[e[i].y]&&e[i].y!=fa){
                        getroot(e[i].y,node);
                        siz[node]+=siz[e[i].y];
                        ms[node]=max(ms[node],siz[e[i].y]);
                  }
            ms[node]=max(ms[node],sum-siz[node]);
            if(ms[node]<ms[root])root=node;
      }
      void getdeep(int node,int fa){
            q[++tail]=dis[node];
            for(int i=LINK[node];i;i=e[i].next)
                  if(!vis[e[i].y]&&e[i].y!=fa){
                        dis[e[i].y]=dis[node]+e[i].v;
                        getdeep(e[i].y,node);
                  }
      }
      int col(int node,int di){
            int tmp=0;
            dis[node]=di;head=1;tail=0;
            getdeep(node,0);
            sort(q+1,q+tail+1);
            while(head<tail){
                  while(q[head]+q[tail]>K&&head<tail)tail--;
                  tmp+=tail-head;
                  head++;
            }
            return tmp;
      }
      void work(int node){
            ans+=col(node,0);
            vis[node]=1;
            for(int i=LINK[node];i;i=e[i].next)
                  if(!vis[e[i].y]){
                        ans-=col(e[i].y,e[i].v);
                        sum=siz[e[i].y];
                        root=0;
                        getroot(e[i].y,node);
                        work(root);
                  }
      }
      void slove(){
            root=0;sum=N;ms[0]=oo;
            getroot(1,0);
            work(root);
      }
      void output(){
            printf("%d\n",ans);
      }
}
int main(){
      //freopen("input.in","r",stdin);
      using namespace solution;
      while(scanf("%d %d",&N,&K)!=EOF){
            init();
            slove();
            output();
      }
      return 0;
}