#include <dreaming.h>
#include <bits/stdc++.h>
#define int long long
using namespace std;
int32_t travelTime(int32_t n, int32_t m, int32_t cost, int32_t A[], int32_t B[], int32_t T[]) {
int ans = 0, t = 0;
vector<int> seen(n), dpu(n), dpb(n), cn;
vector<vector<int>> pref(n), suf(n);
deque<pair<int, int>> cur;
vector<vector<pair<int, int>>> G(n);
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]);
}
function<void(int, int)> dfs1 = [&](int node, int last) {
cn.emplace_back(node);
seen[node] = t;
pref[node].emplace_back(0), suf[node].emplace_back(0);
for (auto x : G[node])
if (x.first != last) {
dfs1(x.first, node);
dpb[node] = max(dpb[node], dpb[x.first] + x.second);
pref[node].emplace_back(dpb[x.first] + x.second);
suf[node].emplace_back(dpb[x.first] + x.second);
}
pref[node].emplace_back(0), suf[node].emplace_back(0);
int s = pref[node].size() - 1;
for (int i = 1; i <= s; ++i)
pref[node][i] = max(pref[node][i], pref[node][i - 1]);
for (int i = s; i; --i)
suf[node][i] = max(suf[node][i], suf[node][i + 1]);
};
function<void(int, int)> dfs2 = [&](int node, int last) {
int ct = 1;
for (auto x : G[node])
if (x.first != last) {
dpu[x.first] = x.second + max(max(pref[node][ct - 1], suf[node][ct + 1]), dpu[node]);
dfs2(x.first, node);
++ct;
}
};
for (int i = 0; i < n; ++i)
if (!seen[i]) {
++t;
cn.clear();
dfs1(i, -1);
dfs2(i, -1);
pair<int, int> ans = {INT_MAX, 0};
for (auto x : cn)
ans = min(ans, {max(dpu[x],dpb[x]),x});
cur.emplace_back(ans);
}
sort(cur.begin(), cur.end());
reverse(cur.begin(), cur.end());
pair<int, int> node = cur.front();
cur.pop_front();
for (auto [c, n] : cur) {
G[n].emplace_back(node.second, cost);
G[node.second].emplace_back(n, cost);
}
vector<int> dp1(n), dp2(n);
function<void(int, int)> dfs = [&](int node, int last) {
for (auto x : G[node])
if (x.first != last) {
dfs(x.first, node);
int cost = dp1[x.first] + x.second;
if (cost >= dp1[node])
dp2[node] = dp1[node], dp1[node] = cost;
else if (cost > dp2[node])
dp2[node] = cost;
}
};
dfs(0, -1);
for (int i = 0; i < n; ++i)
ans = max(ans, dp1[i] + dp2[i]);
return ans;
}
