#include <bits/stdc++.h>
#include "dreaming.h"
using namespace std;
using ll = long long;
using pii = pair<int, int>;
vector<int> h;
int n;
vector<vector<pii>> adj;
void dfs(int u, int p=-1, int w=0) {
h[u] = w;
for (auto [v, pe] : adj[u]) {
if (v==p) continue;
dfs(v, u, w+pe);
}
}
int t;
vector<int> comp;
void dfs1(int u, int p=-1) {
comp.push_back(u);
for (auto [v, w] : adj[u]) {
if (v==p) continue;
dfs1(v, u);
}
}
int travelTime(int N, int m, int L, int A[], int B[], int T[]) {
t=0;
n = N;
adj.assign(n, {});
vector<vector<int>> cmp;
vector<bool> vis(n, false);
for (int i=0; i<m; i++) {
adj[A[i]].push_back({B[i], T[i]});
adj[B[i]].push_back({A[i], T[i]});
}
for (int i=0; i<n; i++) {
if (!vis[i]) {
comp.clear();
dfs1(i);
cmp.push_back(comp);
for (auto x : comp) {
vis[x] = false;
}
}
}
int k = cmp.size();
for (int i=0; i<k-1; i++) {
int u = cmp[i][0];
int v = cmp[i+1][0];
adj[u].push_back({v, L});
adj[v].push_back({u, L});
}
h.assign(n, 0);
dfs(0);
int l=0;
for (int i=0; i<n; i++) {
if (h[i]>h[l]) {
l = i;
}
}
h.assign(n, 0);
dfs(l);
int r = 0;
int mx=0;
for (int i=0; i<n; i++) {
if (h[i]>h[r]) {
r = i;
}
mx = max(mx, h[i]);
}
return mx;
}
