#include "towns.h"
#include "bits/stdc++.h"
using namespace std;
#define fi first
#define se second
#define ll long long
#define dbg(v) cerr<<#v<<" = "<<v<<'\n'
#define vi vector<int>
#define vl vector <ll>
#define pii pair<int,int>
#define mp make_pair
#define db long double
#define pb push_back
#define all(s) s.begin(),s.end()
template < class T > T smin(T &a,T b) {if (a > b) a = b;return a;}
template < class T > T smax(T &a,T b) {if (a < b) a = b;return a;}
const int N = 256;
int D[N][N];
int get(int x,int y) {
if (D[x][y] != -1)
return D[x][y];
return D[x][y] = D[y][x] = getDistance(x,y);
}
int hubDistance(int n, int sub) {
memset(D,-1,sizeof(D));
int x = 0;
for (int i = 0;i < n;++i)
D[i][i] = 0;
for (int i = 0;i < n;++i)
if (get(0,i) > get(0,x))
x = i;
int y = x;
for (int i = 0;i < n;++i)
if (get(x,i) > get(x,y))
y = i;
vi s;
map < int , int > M;
for (int k = 0;k < n;++k)
s.pb((get(x,y) - (get(x,k) - get(y,k))) / 2),++M[s.back()];
sort(all(s));
s.resize(unique(all(s)) - s.begin());
int ans = 2e9;
for (auto it : s)
smin(ans,max(it,D[x][y] - it));
if (sub <= 2)
return ans;
pair < int , pii > bst = mp(-1,mp(-1,-1));
int ds = -1;
for (auto dist : s)
if (max(dist,D[x][y] - dist) == ans) {
int a = 0,b = 0;
for (auto it : M) {
if (it.fi < dist)
a += it.se;
if (dist < it.fi)
b += it.se;
}
if (a < b)
swap(a,b);
auto curr = mp(a + b,mp(a,b));
if (bst > curr)
bst = curr,ds = dist;
}
int dist = ds;
int a = bst.se.fi;
int b = bst.se.se;
if (max(a,b) > (n / 2))
return -ans;
vi v;
for (int k = 0;k < n;++k)
if (get(x,y) - (get(x,k) - get(y,k)) == 2 * dist)
v.pb(k);
int sz = v.size();
vi was(sz,1);
int mx = max(a,b);
for (int i = 0;i < sz;++i)
if (was[i]) {
int cnt = 1;
for (int j = 0;j < sz;++j)
if (was[j]) {
if (get(y,v[i]) + get(y,v[j]) - get(v[i],v[j]) != 2 * dist)
++cnt,was[j] = 0;
}
smax(mx,cnt);
}
if (mx <= (n / 2))
return ans;
return -ans;
}
