#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#define _GLIBCXX_DEBUG
using namespace std;
using std::cout;
using std::cin;
using std::endl;
using ll=long long;
using ld=long double;
ll ILL=1167167167167167167;
const int INF=100000000;
const ll mod=998244353;
#define rep(i,a) for (ll i=0;i<a;i++)
template<class T> using _pq = priority_queue<T, vector<T>, greater<T>>;
template<class T> ll LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> ll UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
void yneos(bool a){if(a) cout<<"YES\n"; else cout<<"NO\n";}

void solve();

//  rainy ~ 雨に打たれて ~
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	
	int t=1;
	//cin>>t;
	rep(i,t) solve();
}

void solve(){
	int N,K;
	cin>>N>>K;
	vector<vector<pair<int,int>>> G(N);
	rep(i,N-1){
		int a,b,c;
		cin>>a>>b>>c;
		a--,b--;
		G[a].push_back({b,c});
		G[b].push_back({a,c});
	}
	vector<int> order={0},seen(N,-1);
	seen[0]=-2;
	rep(i,N){
		int a=order[i];
		for(auto x:G[a]){
			if(seen[x.first]==-1){
				seen[x.first]=a;
				order.push_back(x.first);
			}
		}
	}
	vector<int> size(N),val(N),dp(K+1);
	int sum=0;
	rep(i,N){
		int a=order[N-1-i];
		for(auto x:G[a]){
			if(seen[x.first]!=a) val[a]=x.second;
			else size[a]+=size[x.first];
		}
		if(size[a]==0) size[a]++;
		int v=size[a]*val[a];
		//cout<<val[a]<<" "<<v<<"\n";
		for(int j=K-val[a];j>=0;j--){
			chmax(dp[j+val[a]],dp[j]+v);
		}
		sum+=v;
	}
	cout<<sum+dp[K]<<"\n";
}