using System;
using System.Collections.Generic;
using System.Collections;
using System.Collections.Specialized;
using System.Linq;
using System.Text;
using System.IO;
using System.Reflection;
using static System.Math;
using System.Numerics;
static class Program{
	const int mod=(int)1e9+7;
	const long inf=long.MaxValue-1;
	static List<Tuple<int,int>>[] li;
	static bool[] b;
	static void Main(){
		Sc sc=new Sc();
		var s=sc.Ia;
		int n=s[0],m=n-1,g=(s[1]+1)>>1;
		li=new List<Tuple<int,int>>[n];
		b=new bool[n+1];
		var c=new int[n];
		var dp=new int[n][];
		for(int i=0;i<n;i++){
			li[i]=new List<Tuple<int,int>>();
			dp[i]=new int[g+1];
			dp[i][0]=sc.I;
		}
		for(int i=0;i<m;i++){
			var e=sc.Ia;
			li[e[0]].Add(Tuple.Create(e[1],e[2]));
			li[e[1]].Add(Tuple.Create(e[0],e[2]));
		}
		var h=new int[g+1];
		Fu(0);
		void Fu(int a){
			b[a]=true;
			for(int i=0;i<li[a].Count;i++){
				if(!b[li[a][i].Item1]){
					Fu(li[a][i].Item1);
					Array.Copy(dp[a],h,g+1);
					for(int j = g;j>=li[a][i].Item2;j--) {
						for(int k = 0;k<=g&&j-li[a][i].Item2-k>=0;k++) {
							if(dp[li[a][i].Item1][k]==0){continue;}
							h[j]=Max(h[j],dp[li[a][i].Item1][k]+dp[a][j-li[a][i].Item2-k]);
						}
					}
					Array.Copy(h,dp[a],g+1);
				}
			}
		}
		Console.WriteLine("{0}",dp[0].Max());
	}
}

public class Sc{
	public int I{get{return int.Parse(Console.ReadLine());}}
	public long L{get{return long.Parse(Console.ReadLine());}}
	public double D{get{return double.Parse(Console.ReadLine());}}
	public string S{get{return Console.ReadLine();}}
	public int[] Ia{get{return Array.ConvertAll(Console.ReadLine().Split(),int.Parse);}}
	public long[] La{get{return Array.ConvertAll(Console.ReadLine().Split(),long.Parse);}}
	public double[] Da{get{return Array.ConvertAll(Console.ReadLine().Split(),double.Parse);}}
	public string[] Sa{get{return Console.ReadLine().Split();}}
	public object[] Oa{get{return Console.ReadLine().Split();}}
	public int[] Ia2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),int.Parse);}}
	public int[] Ia3(string a,string b){return Array.ConvertAll((a+Console.ReadLine()+b).Split(),int.Parse);}
	public long[] La2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),long.Parse);}}
	public long[] La3(string a,string b){return Array.ConvertAll((a+Console.ReadLine()+b).Split(),long.Parse);}
	public double[] Da2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),double.Parse);}}
	public double[] Da3(string a,string b){return Array.ConvertAll((a+Console.ReadLine()+b).Split(),double.Parse);}
	public T[] Arr<T>(int n,Func<T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f();}return a;}
	public T[] Arr<T>(int n,Func<int,T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i);}return a;}
	public T[] Arr<T>(int n,Func<string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(Console.ReadLine().Split());}return a;}
	public T[] Arr<T>(int n,Func<int,string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i,Console.ReadLine().Split());}return a;}
}