/*************************************
* author: marvinthang *
* created: 08.03.2023 17:37:48 *
*************************************/
#include <bits/stdc++.h>
#include "towns.h"
using namespace std;
#define fi first
#define se second
#define left ___left
#define right ___right
#define TIME (1.0 * clock() / CLOCKS_PER_SEC)
#define MASK(i) (1LL << (i))
#define BIT(x, i) ((x) >> (i) & 1)
#define __builtin_popcount __builtin_popcountll
#define ALL(v) (v).begin(), (v).end()
#define REP(i, n) for (int i = 0, _n = (n); i < _n; ++i)
#define REPD(i, n) for (int i = (n); i--; )
#define FOR(i, a, b) for (int i = (a), _b = (b); i < _b; ++i)
#define FORD(i, b, a) for (int i = (b), _a = (a); --i >= _a; )
#define FORE(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i)
#define FORDE(i, b, a) for (int i = (b), _a = (a); i >= _a; --i)
#define scan_op(...) istream & operator >> (istream &in, __VA_ARGS__ &u)
#define print_op(...) ostream & operator << (ostream &out, const __VA_ARGS__ &u)
#ifdef LOCAL
#include "debug.h"
#else
#define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
#define DB(...) 23
#define db(...) 23
#define debug(...) 23
#endif
template <class T> scan_op(vector <T>) { for (size_t i = 0; i < u.size(); ++i) in >> u[i]; return in; }
template <class U, class V> scan_op(pair <U, V>) { return in >> u.fi >> u.se; }
template <class U, class V> print_op(pair <U, V>) { return out << '(' << u.first << ", " << u.second << ')'; }
template <class Con, class = decltype(begin(declval<Con>()))> typename enable_if <!is_same<Con, string>::value, ostream&>::type operator << (ostream &out, const Con &con) { out << '{'; for (__typeof(con.begin()) it = con.begin(); it != con.end(); ++it) out << (it == con.begin() ? "" : ", ") << *it; return out << '}'; }
template <size_t i, class T> ostream & print_tuple_utils(ostream &out, const T &tup) { if constexpr(i == tuple_size<T>::value) return out << ")"; else return print_tuple_utils<i + 1, T>(out << (i ? ", " : "(") << get<i>(tup), tup); }
template <class ...U> print_op(tuple<U...>) { return print_tuple_utils<0, tuple<U...>>(out, u); }
template <class A, class B> bool minimize(A &a, B b) { if (a > b) { a = b; return true; } return false; }
template <class A, class B> bool maximize(A &a, B b) { if (a < b) { a = b; return true; } return false; }
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
long long rand(long long l, long long h) { return uniform_int_distribution <long long> (l, h) (rng); }
// end of template
int hubDistance(int N, int sub) {
if (sub == 3) {
vector <vector <int>> dist(N, vector<int>(N, 0));
REP(i, N) REP(j, i) dist[i][j] = dist[j][i] = getDistance(i, j);
int u = 0, v = 0, diameter = 0;
REP(love, 2) {
pair <int, int> f;
REP(i, N) if (i != u) maximize(f, make_pair(dist[i][u], i));
v = u; u = f.se; diameter = f.fi;
}
int res = diameter;
map <int, vector <int>> List;
REP(w, N) if (w != u && w != v) {
int v_to_city = (diameter + dist[v][w] - dist[u][w]) / 2;
List[v_to_city].push_back(w);
minimize(res, max(v_to_city, diameter - v_to_city));
}
int left = 1;
for (auto [d, l]: List) {
if (max(d, diameter - d) == res) {
vector <int> comps;
int right = N - left - (int) l.size();
if (left > N / 2 || right > N / 2) continue;
vector <bool> used(l.size());
bool ok = true;
REP(i, l.size()) if (!used[i]) {
int cnt = 0;
REP(j, l.size()) if (!used[j]) {
if (dist[v][l[i]] + dist[v][l[j]] - 2 * d != dist[l[i]][l[j]]) {
used[j] = true;
++cnt;
}
}
if (cnt > N / 2) {
ok = false;
break;
}
}
if (ok) return res;
}
left += l.size();
}
return -res;
}
int u = 0, v = 0, diameter = 0;
vector <int> dist(N);
int sum = 1;
REP(love, 2) {
pair <int, int> f;
REP(i, N) if (i != u) {
dist[i] = getDistance(u, i);
++sum;
maximize(f, make_pair(dist[i], i));
}
v = u; u = f.se; diameter = f.fi;
}
int res = diameter;
map <int, vector <int>> List;
REP(w, N) if (w != u && w != v) {
int v_to_city = (diameter + dist[w] - getDistance(u, w)) / 2;
++sum;
List[v_to_city].push_back(w);
minimize(res, max(v_to_city, diameter - v_to_city));
}
if (sub < 3) return res;
int left = 1;
vector <bool> used(N);
int x = 0;
for (auto [d, l]: List) {
if (max(d, diameter - d) == res) {
int right = N - left - (int) l.size();
if (left > N / 2 || right > N / 2) continue;
if (sub == 4) {
if (l.size() > N / 2) continue;
return res;
}
if (l.size() <= N / 2) return res;
bool ok = true;
REP(_, 2) {
while (used[l[0]]) shuffle(ALL(l), rng);
used[l[0]] = true;
int cnt = 1;
FOR(i, 1, l.size()) if (!used[l[i]]) {
++sum;
assert(sum <= 5 * N);
if (dist[l[0]] + dist[l[i]] - 2 * d != getDistance(l[0], l[i])) {
used[l[i]] = true;
++cnt;
}
}
if (cnt > N / 2) {
ok = false;
break;
}
}
if (ok) return res;
}
left += l.size();
}
return -res;
}
#ifdef LOCAL
#include "graderlib.c"
int main() {
FILE *f;
f = freopen("towns.in","r",stdin);
assert(f != NULL);
f = freopen("towns.out","w",stdout);
assert(f != NULL);
int ncase, R, N;
int subtask;
int ret;
ret = scanf("%d%d",&subtask,&ncase);
assert(ret == 2);
for (int i = 0; i < ncase; i++) {
ret = scanf("%d",&N);
assert(ret == 1);
_ini_query(N,subtask);
R=hubDistance(N,subtask);
printf("%d\n",R);
}
return 0;
}
#endif
