#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;
vector<bool> vis;
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;
vis.assign(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] = true;
}
}
}
int k = cmp.size();
vector<int> l(k), r(k), best(k);
h.assign(n, 0);
vector<int> disl(n), disr(n);
int ans=0;
for (int i=0; i<k; i++) {
for (auto v : cmp[i]) {
h[v] = 0;
}
dfs(cmp[i][0]);
l[i] = cmp[i][0];
for (auto v : cmp[i]) {
if (h[v] > h[l[i]]) {
l[i] = v;
}
}
for (auto v : cmp[i]) {
h[v] = 0;
}
dfs(l[i]);
r[i] = cmp[i][0];
for (auto v : cmp[i]) {
if (h[r[i]] < h[v]) {
r[i] = v;
}
}
for (auto v : cmp[i]) {
disl[v] = h[v];
h[v] = 0;
}
dfs(r[i]);
for (auto v : cmp[i]) {
disr[v] = h[v];
h[v] = 0;
}
ans = max(ans, disl[r[i]]);
best[i] = cmp[i][0];
for (auto v : cmp[i]) {
int val = max(disl[best[i]], disr[best[i]]);
//if (i==1) cout << best[i] << " " << val << " " << v << " " << max(disl[v], disr[v]) << endl;
if (val > max(disl[v], disr[v])) {
best[i] = v;
}
}
}
vector<int> vals;
for (int i=0; i<k; i++) {
int v = best[i];
int val = max(disl[v], disr[v]);
vals.push_back(val);
}
sort(vals.begin(), vals.end(), greater<int>());
int tmx=0, tsmx=0;
for (int i=0; i<k; i++) {
if (i<2) tmx += vals[i];
if (i>0 && i<3) tsmx+=vals[i];
}
if (k==1) {
return ans;
}
if (k==2) {
if (m==n-1) {
return ans;
}
return tmx+L;
}
return max({
ans, tmx+L, tsmx+2*L
});
}
