#include <bits/stdc++.h> #include <chrono> #define ll long long int #define endl '\n' #define vn vector<ll> #define vi vector<pair <ll,ll>> using namespace std; using namespace std::chrono; const int MAX_N = 1e9 + 7; #define pii pair<ll,ll> const ll INF = 0x3f3f3f3f3f3f3f3f; #define pb push_back #define srt(vp) sort(vp.begin(), vp.end()) ll n,k; vector <vi> adj; int main() { ios::sync_with_stdio(false); cin.tie(nullptr); auto start = high_resolution_clock::now(); cin>>n>>k; adj.resize(n+1); for (int i=0;i<n-1;i++){ ll a,b,c; cin>>a>>b>>c; adj[a].pb({b,c}); adj[b].pb({a,c}); } pair <ll,ll> ans = {MAX_N,0}; for (int mask=0;mask < (1<<n);mask++){ ll count = 0; vn dist(n+1,INF); priority_queue<pair <ll,ll> , vector <pair <ll,ll>>, greater <pair <ll,ll>>>pq; for (int i=0;i<n;i++){ if ((mask >> i) & 1){ count++; pq.push({0,i+1}); dist[i+1]=0; } } vector <bool> visited(n+1,false); while (!pq.empty()){ auto [a,b]=pq.top(); pq.pop(); if (visited[b])continue; visited[b]=true; for (auto &x:adj[b]){ if (dist[x.first]>dist[b]+x.second){ dist[x.first]=dist[b]+x.second; pq.push({dist[x.first],x.first}); } } } bool check = true; for (int i=1;i<=n;i++){ if (dist[i]>k)check=false; } if (check){ ans = min(ans,{count,mask}); } } cout<<ans.first<<endl; ll mask = ans.second; for (int i=0;i<n;i++){ if ((mask >> i) & 1)cout<<i+1<<' '; } cout<<endl; auto stop = high_resolution_clock::now(); auto duration = duration_cast<microseconds>(stop - start); //cout << "Time taken by function: " << duration.count() << " microseconds" << endl; return 0; }