#include <bits/stdc++.h>
#include "dreaming.h"
using namespace std;
int travelTime(int N, int M, int L, int A[], int B[], int T[]) {
vector<vector<pair<int, int>>> adj(N);
for (int i = 0; i < M; ++i) {
adj[A[i]].emplace_back(B[i], T[i]);
adj[B[i]].emplace_back(A[i], T[i]);
}
vector<bool> visit(N);
vector<int> depth(N);
vector<int> pr(N);
vector<int> order;
function<void(int)> dfs = [&](int x) {
order.push_back(x);
visit[x] = true;
for (auto p : adj[x]) {
int y = p.first, w = p.second;
if (y != pr[x]) {
depth[y] = depth[x] + w;
pr[y] = x;
dfs(y);
}
}
};
vector<int> trees;
int ans = 0;
for (int i = 0; i < N; ++i) {
if (!visit[i]) {
order.clear();
depth[i] = 0;
pr[i] = -1;
dfs(i);
int x = i;
for (auto u : order) {
if (depth[u] > depth[x]) {
x = u;
}
}
order.clear();
depth[x] = 0;
pr[x] = -1;
dfs(x);
int y = x;
for (auto u : order) {
if (depth[u] > depth[y]) {
y = u;
}
}
ans = max(ans, depth[y]);
int half = depth[y];
for (int u = y; ~u; u = pr[u]) {
half = min(half, max(depth[u], depth[y] - depth[u]));
}
trees.push_back(half);
}
}
sort(trees.begin(), trees.end(), greater<int>());
if ((int) trees.size() >= 2) {
ans = max(ans, trees[0] + trees[1] + L);
}
if ((int) trees.size() >= 3) {
ans = max(ans, trees[1] + trees[2] + L * 2);
}
return ans;
}
