#include <bits/stdc++.h>
#include "dreaming.h"
using namespace std;
mt19937 rng(chrono::system_clock::now().time_since_epoch().count());
//#undef LOCALKL
#define IO \
ios_base::sync_with_stdio(0);(cin).tie(0);(cout).tie(0)
#define y1 y1_
#define prev prev_
#define all(a) (a).begin(),(a).end()
#define pb push_back
#define eb emplace_back
#define F first
#define S second
#ifdef LOCALKL
#define cerr cerr<<"\33[1;32m"
#define cout cout<<"\33[0m"
#else
#define endl '\n'
#define cerr if(1){}else cerr
#endif
#define OK cout<<"OK\n"<<endl;
#define setpre(k) fixed<<setprecision(k)
#define mmset(k,y) memset(k,y,sizeof(k))
#define sz(x) ((int)(x).size())
using pii = pair<int,int>;
using pll = pair<long long,long long>;
using ull = unsigned long long;
using intt = long long;
using ll = long long;
using ld = long double;
const ll m9 = 998244353;
const ll m7 = 1000000007;
const ll m18 = 1000000000000000000;
const ll i127 = 2139062143;
const ll l127 = 9187201950435737471;
int x,y;
bool fl;
vector<pii>g[100001];
pii mx;
int res, ans;
int d[100001];
void dfs(int v, bool reset)
{
// cerr<<(reset?"1> ":"2> ")<<v<<endl;
for(auto u : g[v])
{
if(d[u.F]==-1)
{
d[u.F] = d[v] + u.S;
mx = max(make_pair(d[u.F], u.F), mx);
dfs(u.F, reset);
}
}
if(reset) d[v]=-1;
}
int dfs1(int v, int par, int dis)
{
if(v==y)
{
fl=1;
return 0;
}
int cdis = 0;
for(auto u : g[v])
if(u.F!=par)
{
cdis = dfs1(u.F, v, dis+u.S)+u.S;
if(fl)
{
res = min(res, max(cdis, dis));
ans = max(ans, cdis+dis);
return cdis;
}
}
return 0;
}
vector<int>c;
int travelTime(int n, int m, int L, int A[], int B[], int T[]) {
memset(d, -1, sizeof(d));
for(int i=0;i<m;i++)
{
g[A[i]].emplace_back(B[i],T[i]);
g[B[i]].emplace_back(A[i],T[i]);
}
for(int i=0;i<n;i++)
if(d[i]==-1)
{
d[i]=0;
mx={0,i};
dfs(i, 1);
x = mx.S;
// cerr<<x<<endl;
mx={0,x};
d[x]=0;
dfs(x, 0);
y = mx.S;
fl=0;
res = INT_MAX;
dfs1(x, -1, 0);
// cerr<<x<<' '<<y<<' '<<res<<endl;
if(x==y) res=0;
c.emplace_back(res);
}
sort(all(c), greater<int>());
if(m<n-2)
ans = max(ans, max(c[0]+c[1]+L, c[1]+c[2]+L+L));
else if(m==n-2)
ans = max(ans, c[0]+c[1]+L);
return ans;
}
