#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define ll long long
#define all(x) (x).begin(), (x).end()
const int mxn = 3e5 + 10;
ll n, k;
vector<pair<ll, ll>> g[mxn];
vector<int> ans;
pair<bool, ll> dfs(int cur, int par = -1, ll dist = 1e16) {
ll mxOver = -1e16, mxUnder = 0;
for (auto [to, weight] : g[cur]) {
if (to == par) continue;
auto res = dfs(to, cur, weight);
if (res.first) mxOver = max(mxOver, res.second);
else mxUnder = max(mxUnder, res.second);
}
pair<bool, ll> res;
if (mxOver >= mxUnder) res = {1, mxOver - dist};
else res = {0, mxUnder + dist};
if (!res.first && res.second > k) {
res = {1, k - dist};
ans.push_back(cur);
}
if (res.first && res.second < 0) res = {0, 0};
return res;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> n >> k;
for (int i = 0; i < n - 1; i++) {
ll f, t, w;
cin >> f >> t >> w;
g[f].push_back({t, w});
g[t].push_back({f, w});
}
dfs(1);
cout << ans.size() << endl;
for (auto x : ans) cout << x << " ";
}
