#ifndef hwe
#include "towns.h"
#endif
#include <bits/stdc++.h>
using namespace std;
#define POPCOUNT(n) (__builtin_popcountll((n)))
#define CLZ(n) (__builtin_clzll((n)))
#define CTZ(n) (__builtin_ctzll((n)))
#define LOG(n) (63 - __builtin_clzll((n)))
#define BIT(n, i) (((n) >> (i)) & 1ll)
#define MASK(i) (1ll << (i))
#define FLIP(n, i) ((n) ^ (1ll << (i)))
#define ON(n, i) ((n) | MASK(i))
#define OFF(n, i) ((n) & ~MASK(i))
#define Int __int128
#define fi first
#define se second
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<long long, long long> pll;
typedef pair<long long, int> pli;
typedef pair<int, long long> pil;
typedef vector<pair<int, int>> vii;
typedef vector<pair<long long, long long>> vll;
typedef vector<pair<long long, int>> vli;
typedef vector<pair<int, long long>> vil;
template <class T1, class T2> bool maximize(T1 &x, T2 y) {
if (x < y) {
x = y;
return true;
}
return false;
}
template <class T1, class T2> bool minimize(T1 &x, T2 y) {
if (x > y) {
x = y;
return true;
}
return false;
}
template <class T> void remove_duplicate(vector<T> &ve) {
sort (ve.begin(), ve.end());
ve.resize(unique(ve.begin(), ve.end()) - ve.begin());
}
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
long long random(long long l, long long r) {
return uniform_int_distribution<long long>(l, r)(rng);
}
template <class T> T random(T r) {
return rng() % r;
}
const int N = 1e6 + 5;
const int MOD = 1e9 + 7;
const int inf = 1e9;
const long long INF = 1e18;
#ifdef hwe
int n;
vii edges;
vector<int> adj[N];
int dep[N], up[N][LG];
void dfs(int u, int fa) {
for (auto v : adj[u]) if (v != fa) {
dep[v] = dep[u] + 1, up[v][0] = u;
for (int i = 1; i < LG; ++i) up[v][i] = up[up[v][i - 1]][i - 1];
dfs(v, u);
}
}
int lca(int u, int v) {
if (dep[u] < dep[v]) swap(u, v);
int delta = dep[u] - dep[v];
for (int i = 0; MASK(i) <= delta; ++i)
if (BIT(delta, i)) u = up[u][i];
if (u == v) return u;
for (int i = LOG(dep[u]); i >= 0; --i)
if (up[u][i] != up[v][i]) {
u = up[u][i], v = up[v][i];
}
return up[u][0];
}
int getDistance(int u, int v) {
return dep[u] + dep[v] - 2 * dep[lca(u, v)];
}
#endif
int hubDistance(int n, int sub) {
vector<vector<int>> dist(n, vector<int>(n, 0));
int u = -1, v = -1, diameter = 0;
for (int i = 0; i < n; ++i) for (int j = i + 1; j < n; ++j) {
dist[i][j] = dist[j][i] = getDistance(i, j);
if (maximize(diameter, dist[i][j])) u = i, v = j;
}
int R = inf;
for (int i = 0; i < n; ++i) if (i != u && i != v) {
int tmp = (dist[i][u] + dist[i][v] - dist[u][v]) / 2;
minimize(R, max(dist[i][u] - tmp, dist[i][v] - tmp));
}
return R;
}
#ifdef hwe
signed main() {
ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
return 0;
}
#endif
