学步园

#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdio>
#define inf 0x7fffffff
using namespace std;
inline int read(){
    int x=0,f=1;char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
    return x*f;
}
int n,K,cnt,sum,ans,root;
int head[10001],deep[10001],d[10001],f[10001],son[10001];
bool vis[10001];
struct edge{int to,next,v;}e[20001];
inline void ins(int u,int v,int w){
	e[++cnt]=(edge){v,head[u],w};head[u]=cnt;
	e[++cnt]=(edge){u,head[v],w};head[v]=cnt;
}
inline void getroot(int x,int fa){
	son[x]=1;f[x]=0;
	for(int i=head[x];i;i=e[i].next){
		if(e[i].to==fa||vis[e[i].to])continue;
		getroot(e[i].to,x);
		son[x]+=son[e[i].to];
		f[x]=max(f[x],son[e[i].to]);
	}
	f[x]=max(f[x],sum-son[x]);
	if(f[x]<f[root])root=x;
}
inline void getdeep(int x,int fa){
	deep[++deep[0]]=d[x];
	for(int i=head[x];i;i=e[i].next){
		if(e[i].to==fa||vis[e[i].to])continue;
		d[e[i].to]=d[x]+e[i].v;
		getdeep(e[i].to,x);
	}
}
inline int cal(int x,int now){
	d[x]=now;deep[0]=0;
	getdeep(x,0);
	sort(deep+1,deep+deep[0]+1);
	int t=0,l,r;
	for(l=1,r=deep[0];l<r;){
		if(deep[l]+deep[r]<=K)t+=r-l,l++;
		else r--;
	}
	return t;
}
inline void work(int x){
	ans+=cal(x,0);
	vis[x]=1;
	for(int i=head[x];i;i=e[i].next){
		if(vis[e[i].to])continue;
		ans-=cal(e[i].to,e[i].v);
		sum=son[e[i].to];
		root=0;
		getroot(e[i].to,root);
		work(root);
	}
}
int main(){
	while(1){
		ans=root=cnt=0;
		memset(vis,0,sizeof(vis));
		memset(head,0,sizeof(head));
		n=read();K=read();
		if(n==0)break;
		for(int i=1;i<n;++i){
			int u=read(),v=read(),w=read();
			ins(u,v,w);
		}
		sum=n;f[0]=inf;
		getroot(1,0);
		work(root);
		printf("%d\n",ans);
	}
	return 0;
}