#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;
vn ans;
pair <ll,ll> dfs(ll n, ll p , ll d){
ll cover=0;
ll nah = 0;
for (auto &x:adj[n]){
if (x.first==p)continue;
auto [child,dist]=x;
auto [status,far]=dfs(child,n,dist);
if (status){
cover = max(cover,far);
}
else nah = max(far,nah);
}
if (cover >= nah){
if (cover >= d)return {1,cover-d};
else return {0,0};
}
else{
if (nah + d <=k)return {0,nah+d};
else{
ans.pb(n);
if (k >=d)return {1,k-d};
else return {0,0};
}
}
}
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});
}
if (dfs(1,0,0).first==0)ans.pb(1);
auto stop = high_resolution_clock::now();
auto duration = duration_cast<microseconds>(stop - start);
//cout << "Time taken by function: " << duration.count() << " microseconds" << endl;
return 0;
}
