// I also thought that there was a small chance that she likes me back.
#include <bits/stdc++.h>
using namespace std;
// Do you think you'll ever remember me someday, or will I just fade away from your memory?
#define LIFESUCK ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define ll long long
#define str string
#define mll map<ll, ll>
#define vll vector<ll>
#define pll pair<ll, ll>
#define fi first
#define se second
#define all(c) c.begin(), c.end()
#define pb push_back
#define sz(s) s.size()
#define debug cout << "I Love You\n";
#define fu(i, a, b) for (ll i = a; i <= b; i++)
#define fd(i, b, a) for (ll i = b; i >= a; i--)
#define Bitc(msk, j) ((msk >> j) & 1)
#define _log(x) 31 - __builtin_clz(x)
#define LoveTime chrono::steady_clock::now().time_since_epoch().count()
const ll Mod = 998244353;
const ll inf = (1ll << 30);
const ll lnf = (1ll << 60);
// When time passes and things change... will you still remember someone like me?
int64_t add(ll& a, ll b) {
a += b;
if (a >= Mod) a %= Mod;
while (a < 0) a += Mod;
return a;
}
int64_t mul(ll a, ll b) {
a = 1ll * a * b % Mod;
return a;
}
template <class X, class Y>
bool minimize(X& x, Y y) {
X eps = 1e-9;
if (x > y + eps) {
x = y;
return 1;
}
return 0;
}
template <class X, class Y>
bool maximize(X& x, Y y) {
X eps = 1e-9;
if (x + eps < y) {
x = y;
return 1;
}
return 0;
}
// I wonder… will I just become a distant memory to you one day?
#define mxn 300'007
ll n, k, g[mxn];
vector<pll> graph[mxn];
struct Edge {
ll u, v, w;
} edge[mxn];
namespace Love1 {
bool check() {
fu(i, 2, n) if(edge[i].w <= k) return 0;
return 1;
}
void DreamyLove () {
cout << n << '\n';
fu(i, 1, n) cout << i << ' ';
//
}
}
namespace Love23 {
bool check() {
return (n <= 17);
}
ll minDist[mxn];
void DreamyLove () {
ll sad = lnf;
ll trace;
fu(msk, 1, (1 << n) - 1) {
ll cnt = __builtin_popcount(msk);
if(cnt >= sad) continue;
priority_queue<pll, vector<pll>, greater<pll>> Q;
fu(i, 1, n) minDist[i] = lnf;
fu(i, 0, n - 1) if(Bitc(msk, i)) Q.push({0, i + 1}), minDist[i + 1] = 0;
while(!Q.empty()) {
auto[d, u] = Q.top(); Q.pop();
if(d > minDist[u]) continue;
for(auto&[v, w]: graph[u]) {
if(minDist[v] <= minDist[u] + w) continue;
minDist[v] = minDist[u] + w;
Q.push({minDist[v], v});
}
}
bool ok = 1;
fu(i, 1, n) if(minDist[i] > k) ok = 0;
if(ok) sad = cnt, trace = msk;
}
cout << sad << '\n';
fu(i, 0, n - 1) if(Bitc(trace, i)) cout << i + 1 << ' ';
//
}
}
// The world is still beautiful, only it’s a pity that you are no longer among the living.
void lovesper(const ll& TestCase) {
cin >> n >> k;
fu(i, 2, n) {
ll u, v, w;cin >> u >> v >> w;
edge[i] = {u, v, w};
graph[u].pb({v, w});
graph[v].pb({u, w});
}
if(Love1::check()) {
Love1::DreamyLove();
return;
}
if(Love23::check()) {
Love23::DreamyLove();
return;
}
}
// In the future, each of us will have our own path..
// ...But no matter where we go, we will always be a beautiful part of each other’s memories.
signed main() {
LIFESUCK
#define name "lovesper"
// freopen(name".inp", "r", stdin);
// freopen(name".out", "w", stdout);
// carr.close();
ll Test = 1;
// cin >> Test;
fu(i, 1, Test) {
lovesper(i);
if (i < Test) cout << '\n';
}
return 0;
}
