#include <bits/stdc++.h>
#include "dreaming.h"
using namespace std;
const int N = 1e5 + 10;
vector<int> adj[N], cost[N], R;
int vis[N], ans, r, f[N], g[N];
void dfs(int u, int par) {
vis[u] = 1;
for(int i = 0; i < adj[u].size(); i++) {
int v = adj[u][i], c = cost[u][i];
if(v == par) continue;
dfs(v, u);
f[u] = max(f[u], f[v] + c);
}
}
void dfs2(int u, int par, int D) {
int m1 = D, m2 = D;
for(int i = 0; i < adj[u].size(); i++) {
int v = adj[u][i], c = cost[u][i];
if(v == par) continue;
m2 = max(m2, f[v] + c);
if(m2 > m1) swap(m1, m2);
} g[u] = m1;
r = min(r, g[u]);
for(int i = 0; i < adj[u].size(); i++) {
int v = adj[u][i], c = cost[u][i];
if(v == par) continue;
dfs2(v, u, (f[v] + c == m1 ? m2 : m1) + c);
}
}
int travelTime(int N, int M, int L, int A[], int B[], int T[]) {
for(int i = 0; i < M; i++) {
int u = A[i], v = B[i], c = T[i];
adj[u].push_back(v);
adj[v].push_back(u);
cost[u].push_back(c);
cost[v].push_back(c);
}
for(int i = 0; i < N; i++) if(!vis[i]) {
dfs(i, -1); r = INT_MAX;
dfs2(i, -1, 0);
R.push_back(r);
}
sort(R.begin(), R.end(), greater<int>());
for(int i = 0; i < N; i++) ans = max(ans, g[i]);
if(R.size() > 1) ans = max(ans, R[0] + R[1] + L);
if(R.size() > 2) ans = max(ans, R[1] + R[2] + 2*L);
return ans;
}
