#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> cmp;
void dfs1(int u, int p=-1) {
cmp[u] = t;
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, {});
cmp.assign(n, -1);
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 (cmp[i] == -1) {
dfs1(i);
t++;
}
}
vector<int> l(2, 0), r(2, 0);
t=0;
for (int i=0; i<n; i++) {
if (cmp[i] == t) {
h.assign(n, 0);
dfs(i);
l[t] = i;
for (int j=0; j<n; j++) {
if (cmp[j] == cmp[i] && h[j] > h[l[t]]) {
l[t] = j;
}
}
h.assign(n, 0);
dfs(l[t]);
//cerr << t << endl;
r[t] = i;
for (int j=0; j<n; j++) {
if (cmp[j] == cmp[i] && h[j] > h[r[t]]) {
r[t] = j;
}
}
t++;
}
}
vector<int> disl, disr;
h.assign(n, 0);
dfs(l[0]);
disl = h;
h.assign(n, 0);
dfs(r[0]);
disr = h;
int best = 2e9;
for (int i=0; i<n; i++) {
if (cmp[i] == 0) {
best = min(best, max(disl[i], disr[i]));
}
}
//cout << best << endl;
h.assign(n, 0);
dfs(l[1]);
disl = h;
h.assign(n, 0);
dfs(r[1]);
disr = h;
int ans = 2e9;
for (int i=0; i<n; i++) {
if (cmp[i] == 1) {
//cout << i << " " << disl[i] << " " << disr[i] << endl;
ans = min(ans, best+L+max(disl[i], disr[i]));
}
}
return ans;
}
