#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define all(a) (a).begin(), (a).end()
#define replr(i, a, b) for (int i = int(a); i <= int(b); ++i)
#define reprl(i, a, b) for (int i = int(a); i >= int(b); --i)
#define rep(i, n) for (int i = 0; i < int(n); ++i)
#define mkp(a, b) make_pair(a, b)
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> PII;
typedef vector<int> VI;
typedef vector<PII> VPI;
typedef vector<VI> VVI;
typedef vector<VVI> VVVI;
typedef vector<VPI> VVPI;
typedef pair<ll, ll> PLL;
typedef vector<ll> VL;
typedef vector<PLL> VPL;
typedef vector<VL> VVL;
typedef vector<VVL> VVVL;
typedef vector<VPL> VVPL;
template<class T> T setmax(T& a, T b) {if (a < b) return a = b; return a;}
template<class T> T setmin(T& a, T b) {if (a < b) return a; return a = b;}
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template<class T>
using indset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#include "dreaming.h"
int n, m, L;
VVPI gp;
void dfs(int u, int p, VI& dist, VI& comp) {
comp.pb(u);
for (auto[v, w] : gp[u]) if (v != p) {
dist[v] = dist[u] + w;
dfs(v, u, dist, comp);
}
}
void dfs(int u, int p, VI& dist) {
for (auto[v, w] : gp[u]) if (v != p) {
dist[v] = dist[u] + w;
dfs(v, u, dist);
}
}
int amenaheru(VI& comp, VI& dist) {
int ret;
int mx = -2e9;
for (int u : comp) if (dist[u] > mx) {
ret = u;
mx = dist[u];
}
return ret;
}
int amenamejtex(VI& comp, VI& maxdist) {
int ret = 2e9;
for (int u : comp) setmin(ret, maxdist[u]);
return ret;
}
int travelTime(int N, int M, int L_arg, int A[], int B[], int T[]) {
n = N;
m = M;
L = L_arg;
gp = VVPI(n);
rep(i, m) {
int u = A[i];
int v = B[i];
int w = T[i];
gp[u].pb({v, w});
gp[v].pb({u, w});
}
VI dist(n, 2e9);
VI distd1(n);
VI distd2(n);
VI maxdist(n);
int globald = 0;
VVI comp;
rep(u, n) if (dist[u] == 2e9) {
dist[u] = 0;
comp.pb(VI());
dfs(u, -1, dist, comp.back());
int d1 = amenaheru(comp.back(), dist);
dfs(d1, -1, distd1);
int d2 = amenaheru(comp.back(), distd1);
dfs(d2, -1, distd2);
for (int u : comp.back()) maxdist[u] = max(distd1[u], distd2[u]);
int diameter = distd1[d2];
setmax(globald, diameter);
/*cout << "COMPONENT: ";*/
/*for (int u : comp.back()) cout << u << " "; cout << endl;*/
/*cout << "DIAMETER: " << d1 << " " << d2 << " " << distd1[d2] << endl;*/
/*cout << "FARTHEST PATH LENGTH FROM " << endl;*/
/*for (int u : comp.back()) {*/
/* cout << u << ": " << maxdist[u] << endl;*/
/*}*/
/*cout << endl;*/
}
/*if (comp.size() > 2) {*/
/* VI a(3, 0);*/
/* rep(u, n) for (auto[v, w] : gp[u]) {*/
/* if (u < v) a.pb(w);*/
/* }*/
/* sort(all(a));*/
/* reverse(all(a));*/
/* VI b;*/
/* b.pb(a[0]);*/
/* b.pb(a[1]+L);*/
/* b.pb(a[2]+L);*/
/* sort(all(b));*/
/* reverse(all(b));*/
/* return b[0] + b[1];*/
/*}*/
VI mid;
for (VI& c : comp) {
mid.pb(amenamejtex(c, maxdist));
}
int answer = 2e9;
int mxi;
int mx = 0;
rep(i, comp.size()) {
if (mid[i] > mx) {
mxi = i;
mx = mid[i];
}
}
replr(i, mxi, mxi) {
int diameter = globald;
VI children;
children.pb(0);
children.pb(mid[i]);
rep(j, comp.size()) if (j != i) {
children.pb(mid[j] + L);
}
sort(all(children));
reverse(all(children));
setmax(diameter, children[0] + children[1]);
/*cout << "IF THE CENTER IS " << i << ", THE DIAMETER IS " << diameter << endl;*/
setmin(answer, diameter);
}
return answer;
}
