#include "dreaming.h"
#include <bits/stdc++.h>
using namespace std;
const int mxN = 1e5;
int c, dp[mxN], dpr[mxN], mn[mxN], vis[mxN];
vector<pair<int, int>> adj[mxN];
void dfs(int u, int p){
vis[u] = 1;
for(auto [v, w] : adj[u]) if(v != p) dfs(v, u), dp[u] = max(dp[u], dp[v] + w);
}
void dfs1(int u, int p){
mn[c] = min(mn[c], max(dp[u], dpr[u]));
pair<int, int> mx, smx;
for(auto [v, w] : adj[u]){
if(v == p) continue;
if(dp[v] + w > mx.first){
smx = mx;
mx = {dp[v] + w, v};
}else if(dp[v] + w > smx.first){
smx = {dp[v] + w, v};
}
}
for(auto [v, w] : adj[u]){
if(v == p) continue;
dpr[v] = dpr[u] + w;
if(v == mx.second) dpr[v] = max(dpr[v], smx.first + w);
else dpr[v] = max(dpr[v], mx.first + w);
dfs1(v, u);
}
}
int travelTime(int N, int M, int L, int A[], int B[], int T[]){
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++) mn[i] = INT_MAX;
for(int i = 0;i<N;i++){
if(!vis[i]){
dfs(i, i);
dfs1(i, i);
++c;
}
}
int mx = 0, smx = 0;
for(int i = 0;i<c;i++){
if(mn[i] > mx){
smx = mx;
mx = mn[i];
}else if(mn[i] > smx){
smx = mn[i];
}
}
int ans = mx + smx + L;
for(int i = 0;i<N;i++) ans = max(ans, dp[i] + dpr[i]);
return ans;
}
