#include "dreaming.h"
#include<bits/stdc++.h>
using namespace std;
vector<pair<int,int>> adj[100100];
bitset<100100> vis,vis2;
int mxd[100100], MX, MN;
vector<int> lens;
void dfs1(int n){
vis[n]=1;
for(auto [i,j]:adj[n])if(!vis[i])
dfs1(i), mxd[n]=max(mxd[n],mxd[i]+j);
}
void dfs2(int n,int fromp){
vis2[n]=1,MX=max(MX,fromp);
MN=min(MN,max(fromp,mxd[n]));
vector<int>pre,suf;
for(auto[i,j]:adj[n])if(!vis2[i])
pre.push_back(mxd[i]+j),
suf.push_back(mxd[i]+j);
pre.insert(pre.begin(),0);
suf.push_back(0);
for(int i=1;i<pre.size();i++)
pre[i]=max(pre[i],pre[i-1]);
for(int j=pre.size()-1;j--;)
suf[j]=max(suf[j],suf[j+1]);
int CC=0;
for(auto[i,j]:adj[n])if(!vis2[i]) CC++,
dfs2(i,max({fromp,pre[CC-1],suf[CC]})+j);
}
void solve(int n){
for(int i=0;i<n;i++)
if(!vis[i]) MN=1e9,dfs1(i),
dfs2(i,0),lens.push_back(MN);
}
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]});
solve(N);
sort(lens.rbegin(),lens.rend());
if(lens.size()==1)
return MX;
else if(lens.size()==2)
return max(MX,lens[0]+lens[1]+L);
else return max(MX,lens[1]+L+max(lens[0],lens[2]+L));
}
