#include "dreaming.h"
#include <bits/stdc++.h>
#define ll long long
#define ull unsigned ll
#define f first
#define s second
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pb push_back
#define epb emplace_back
using namespace std;
const int nmax = 200001;
vector <vector <pair<ll, ll> > > g(nmax);
int dp[nmax][3];
vector <bool> used(nmax);
vector <int> cmp;
void dfs(int v, int e = -1){
used[v] = true;
cmp.pb(v);
for(auto x : g[v]){
int to = x.f;
int len = x.s;
if(used[to]) continue;
dfs(to, v);
if(dp[v][0] < dp[to][0] + len){
swap(dp[v][0], dp[v][1]);
dp[v][2] = to;
dp[v][0] = dp[to][0] + len;
}
else dp[v][1] = max(dp[v][1], dp[to][0] + len);
}
}
void reroot(int v, int e){
for(auto x : g[v]){
int to = x.f;
int len = x.s;
if(to == e) continue;
int mx = 0;
if(dp[v][2] == to){
mx = dp[v][1] + len;
}
else mx = dp[v][0] + len;
if(dp[to][0] < mx)
swap(dp[to][0], dp[to][1]), dp[to][2] = v, dp[to][0] = mx;
else dp[to][1] = max(dp[to][1], mx);
reroot(to, v);
}
}
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], w = T[i];
g[u].pb({v, w});
g[v].pb({u, w});
}
int ans = 0;
multiset <ll> st;
for(int i = 0; i < N; i++){
if(used[i]) continue;
dfs(i);
reroot(i, i);
int mn = 1e9;
for(int to : cmp){
ans = max(ans, dp[to][0]);
mn = min(mn, dp[to][0]);
}
st.insert(mn);
cmp.clear();
}
int a, b, c;
a = b = c = -1e9;
if(st.size() >= 2){
a = *st.rbegin();
st.erase(st.find(a));
b = *st.rbegin();
st.erase(st.find(b));
ans = max(ans, a + b + L);
}
if(st.size() >= 1){
c = *st.rbegin();
ans = max(ans, b + c + 2 * L);
}
return ans;
}
