#include<bits/stdc++.h>
using namespace std;
#define ALL(x) begin(x),end(x)
#define rep(i,n) for(int i=0;i<(n);i++)
#define debug(v) cout<<#v<<":";for(auto x:v){cout<<x<<' ';}cout<<endl;
#define mod 1000000007
using ll=long long;
const int INF=1000000000;
const ll LINF=1001002003004005006ll;
int dx[]={1,0,-1,0},dy[]={0,1,0,-1};
// ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
template<class T>bool chmax(T &a,const T &b){if(a<b){a=b;return true;}return false;}
template<class T>bool chmin(T &a,const T &b){if(b<a){a=b;return true;}return false;}

struct IOSetup{
    IOSetup(){
        cin.tie(0);
        ios::sync_with_stdio(0);
        cout<<fixed<<setprecision(12);
    }
} iosetup;

template<typename T>
ostream &operator<<(ostream &os,const vector<T>&v){
    for(int i=0;i<(int)v.size();i++) os<<v[i]<<(i+1==(int)v.size()?"":" ");
    return os;
}
template<typename T>
istream &operator>>(istream &is,vector<T>&v){
    for(T &x:v)is>>x;
    return is;
}

// graph template
// ref : https://ei1333.github.io/library/graph/graph-template.cpp
template<typename T=int>
struct Edge{
    int from,to;
    T w;
    int idx;
    Edge()=default;
    Edge(int from,int to,T w=1,int idx=-1):from(from),to(to),w(w),idx(idx){}
    operator int() const{return to;}
};

template<typename T=int>
struct Graph{
    vector<vector<Edge<T>>> g;
    int V,E;
    Graph()=default;
    Graph(int n):g(n),V(n),E(0){}

    size_t size(){
        return g.size();
    }
    void resize(int k){
        g.resize(k);
    }
    inline const vector<Edge<T>> &operator[](int k)const{
        return (g.at(k));
    }
    inline vector<Edge<T>> &operator[](int k){
        return (g.at(k));
    }
    void add_directed_edge(int from,int to,T cost=1){
        g[from].emplace_back(from,to,cost,E++);
    }
    void add_edge(int from,int to,T cost=1){
        g[from].emplace_back(from,to,cost,E);
        g[to].emplace_back(to,from,cost,E++);
    }
    void read(int m,int pad=-1,bool weighted=false,bool directed=false){
        for(int i=0;i<m;i++){
            int u,v;cin>>u>>v;
            u+=pad,v+=pad;
            T w=T(1);
            if(weighted) cin>>w;
            if(directed) add_directed_edge(u,v,w);
            else         add_edge(u,v,w);
        }
    }
};


void fill(int pre,int cur,Graph<ll> &G,vector<ll> &dis){
    for(auto &e:G[cur])if(pre!=e){
        dis[e]=dis[cur]+e.w;
        fill(cur,e,G,dis);
    }
}


signed main(){
    int N,K;cin>>N>>K;    

    Graph<ll> g(N);
    rep(i,N-1){
        int u,v;ll c;cin>>u>>v>>c;u--,v--;
        g.add_edge(u,v,c);
    }

    vector<ll> leaves(N,0);
    function<void(int,int)> budweiser=[&](int pre,int cur){
        if(pre!=-1 and g[cur].size()==1) leaves[cur]++;

        for(auto &e:g[cur])if(pre!=e){
            budweiser(cur,e);
            leaves[cur]+=leaves[e];
        }
    };
    
    budweiser(-1,0);
    
    Graph<ll> t(N);
    function<void(int,int)> haineken=[&](int pre,int cur){
        for(auto &e:g[cur])if(pre!=e){
            t.add_edge(e.from,e.to,e.w*leaves[e]);
            haineken(cur,e);
        }
    };

    haineken(-1,0);

    ll res=0;
    rep(st,N){
        vector<ll> dis(N),add(N);
        dis[st]=0;
        add[st]=0;
        fill(-1,st,g,dis);
        fill(-1,st,t,add);

        rep(gl,N){
            if(dis[gl]<=K) chmax(res,add[gl]);
        }
    }

    ll ans=0;
    rep(i,N){
        for(auto &e:t[i]) ans+=e.w;
    }
    ans/=2;
    ans+=res;
    cout<<ans<<endl;
    return 0;
}