#include <bits/stdc++.h>
#include "dreaming.h"
using namespace std;
#define ll long long
#define ff first
#define ss second
#define mp make_pair
const ll N_ = 1e5+7;
vector<vector<pair<ll,ll>>> a;
vector<ll> maxdistree;
bool st[N_];
pair<ll,ll> disn[N_];
ll maketree(ll p)
{
st[p] = 1;
ll x = 0,y = 0;
for(auto v : a[p])
{
if(st[v.ss])continue;
ll k = maketree(v.ss) + v.ff;
if(k > x){y = x;x = k;}
else if(k > y)y = k;
}
disn[p].ff = x;
disn[p].ss = y;
return x;
}
ll maxtree(ll p,ll k,ll ans)
{
if(k > ans)return ans;
k = max(k,disn[p].ss);
ans = max(disn[p].ff,k);
ll to = -1;
for(auto v : a[p])
{
if(v.ff + disn[v.ss].ff == disn[p].ff)
{
to = v.ss;
k += v.ff;
break;
}
}
if(to == -1)return ans;
return maxtree(to,k,ans);
}
ll solvefor1(ll n)
{
ll ans = 0;
for(ll i = 0;i < n;i++)ans = max(ans,disn[i].ff + disn[i].ss);
return ans;
}
int travelTime(int N, int M, int L, int A[], int B[], int T[])
{
a.resize(N);
for(ll i = 0;i < M;i++)
{
a[A[i]].push_back(mp(T[i],B[i]));
a[B[i]].push_back(mp(T[i],A[i]));
}
for(ll i = 0;i < N;i++)st[i] = 0;
for(ll i = 0;i < N;i++)
{
if(!st[i]){
maketree(i);
ll x = maxtree(i,0,1e18);
maxdistree.push_back(x);
}
}
sort(maxdistree.begin(),maxdistree.end(),greater<int>());
if(maxdistree.size() == 1)return solvefor1(N);
if(maxdistree.size() == 2)return max(maxdistree[0] + maxdistree[1] + L,solvefor1(N));
return max(solvefor1(N),max(maxdistree[0] + maxdistree[1] + L,maxdistree[2] + maxdistree[1] + 2 * L));
}
