#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 "longesttrip.h"
bool samecomp(VI a, VI b) {
return !are_connected(a, b);
}
VI longest_trip(int N, int D) {
int n = N;
VI group(n, -1);
int last = 0;
rep(u, n) if (group[u] == -1) {
group[u] = last;
rep(v, n) if (group[v] == -1) {
if (samecomp({u}, {v})) group[v] = last;
}
last++;
}
VVI comp(last);
rep(u, n) comp[group[u]].pb(u);
/*cout << "components" << endl;*/
/*rep(i, last) {*/
/* for (int x : comp[i]) cout << x << " ";*/
/* cout << endl;*/
/*}*/
/*cout << "components" << endl;*/
int prev = -1;
VI ans;
rep(_, 3) {
rep(i, last) {
assert(comp[i].size() <= 2);
if (comp[i].size() && i != prev) {
ans.pb(comp[i].back());
comp[i].pop_back();
prev = i;
}
}
}
return ans;
}
