#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;
}
