#include <bits/stdc++.h>
#include "dreaming.h"
#define REP(i, n) for (int i = 0, _b = (n); i < _b; i++)
#define FOR(i, a, b) for (int i = a, _b = (b); i <= _b; i++)
#define pb push_back
#define szx(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()
using namespace std;
#define pii pair<int, int>
#define ll long long
vector<pii> adj[100000];
vector<ll> dis(100000, -1);
ll ans = 0;
ll mx = 0, d = 0;
int par[100000];
void dfs(int u, int p = -1) {
if (mx < dis[u]) mx = dis[u], d = u;
par[u] = p;
for (auto& [v, w] : adj[u]) {
if (v != p) {
dis[v] = dis[u] + w;
dfs(v, u);
}
}
}
int travelTime(int N, int M, int L, int A[], int B[], int T[]) {
REP(i, M) {
adj[A[i]].pb({B[i], T[i]});
adj[B[i]].pb({A[i], T[i]});
}
vector<ll> half;
// cout << dis[0] <<
REP(i, N) if (dis[i] == -1) {
mx = -1;
d = 0;
dis[i] = 0;
dfs(i);
int d1 = d;
mx = -1, d = 0;
dis[d1] = 0;
dfs(d1);
int d2 = d;
ans = max(ans, mx);
ll ans1 = LLONG_MAX;
for (int u = d2; u != -1; u = par[u]) ans1 = min(max(dis[u], mx - dis[u]), ans1);
// for (int u = d2; u != -1; u = par[u]) { cout << u << ' '; };
// cout << endl;
half.pb(ans1);
// cout << ans1 << ' ';
}
sort(all(half), greater<ll>());
FOR(i, 1, szx(half) - 1) { ans = max(ans, half[0] + i * L + half[i]); }
// for (int i : half) cout << i << ' ';
// cout << endl;
return ans;
}
// int main() {
// int N = 12;
// int M = 8;
// int L = 2;
// int A[]{0, 8, 2, 5, 5, 1, 1, 10};
// int B[]{8, 2, 7, 11, 1, 3, 9, 6};
// int T[]{4, 2, 4, 3, 7, 1, 5, 3};
// int x = travelTime(N, M, L, A, B, T);
// // REP(i, N) { cout << dis[i] << ' '; }
// cout << x;
// }
