#include<bits/stdc++.h> 
using namespace std;
const int mod=1e9+7;
int main(){
  int N,K;
  cin>>N>>K;
  vector<vector<pair<int,int>>>g(N);
  for(int i=0,a,b,c;i<N-1;i++){
    cin>>a>>b>>c;
    a--,b--;
    g[a].push_back({b,c});
    g[b].push_back({a,c});
  }
  queue<int>bfs;
  vector<tuple<int,int,int>>ki(N);
  bfs.push(0);
  vector<int>dist(N,1e9),leaf;
  dist[0]=0;
  while(bfs.size()){
    int t=bfs.front();
    bfs.pop();
    bool ha=true;
    for(auto i:g[t]){
      if(dist[i.first]>dist[t]+i.second){
        dist[i.first]=dist[t]+i.second;
        ki[i.first]={t,i.second,0};
        ha=false;
        bfs.push(i.first);
      }
    }
    if(ha)leaf.push_back(t);
  }
  for(int i:leaf){
    int t=i;
    while(t!=0){
      get<2>(ki[t])++;
      t=get<0>(ki[t]);
    }
  }
  vector<int>dp(K+1);
  for(int i=1;i<N;i++){
    for(int j=K;j>=0;j--){
      if(get<1>(ki[i])<=j){
        dp[j]=max(dp[j],dp[j-get<1>(ki[i])]+get<1>(ki[i])*get<2>(ki[i]));
      }
    }
  }
  int ans=dp.back();
  for(int i:leaf){
    ans+=dist[i];
  }
  cout<<ans<<'\n';
}