#include<bits/stdc++.h>
using namespace std;
#define int long long
#define nl '\n'
const int N = 3e5+1;
int k;
vector<pair<int,int>> g[N];
vector<int> ans;
pair<int,int> dfs(int v, int p, int d){
int mx_ov = -1, mx_un = 0;
for(auto [ch, w] : g[v]){
if(ch == p) continue;
auto [tf, x] = dfs(ch, v, w);
if(tf) mx_ov = max(mx_ov, x);
else mx_un = max(mx_un, x);
}
if(mx_ov >= mx_un){
if(mx_ov >= d) return {1, mx_ov - d};
else return {0, 0};
}else{
if(mx_un + d <= k) return {0, mx_un + d};
else{
ans.push_back(v);
if(k >= d) return {1, k-d};
else return {0, 0};
}
}
}
inline void solve(){
int n;
cin>>n>>k;
for(int i=1; i<n; i++){
int a, b, w;
cin>>a>>b>>w;
g[a].push_back({b, w});
g[b].push_back({a, w});
}
if(dfs(1, 0, 0).first == 0) ans.push_back(1);
cout<<ans.size()<<nl;
for(int x : ans) cout<<x<<" ";
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(NULL);cout.tie(NULL);
int t = 1;
//cin>>t;
while(t--) solve();
return 0;
}
