#include "towns.h"
#include<bits/stdc++.h>
using namespace std;
const int MAXN = 310;
int dist[MAXN][MAXN];
int marc[MAXN][MAXN];
int getD(int i, int j){
if(marc[i][j]) return dist[i][j];
marc[i][j] = marc[j][i] = 1;
if(i == j) return dist[i][j] = dist[j][i] = 0;
return dist[i][j] = dist[j][i] = getDistance(i, j);
}
int hubDistance(int N, int sub) {
int p1 = 0, p2 = 0;
int maxi = 0;
memset(dist, 0, sizeof(dist));
memset(marc, 0, sizeof(marc));
for(int i = 0; i < N; i++){
int aux = getD(0, i);
if(aux > maxi) p1 = i, maxi = aux;
}
maxi = 0;
for(int i = 0; i < N; i++)
if(getD(p1, i) > maxi) maxi = getD(p1, i), p2 = i;
int diam = getD(p1, p2);
int ans = 1e8;
for(int i = 0; i < N; i++){
int x = (diam + getD(p1, i) - getD(p2, i)) / 2;
ans = min(ans, max(x, diam - x));
}
if(sub <= 2) return ans;
int lSize = 0, rSize = 0;
vector<int> lMid, rMid;
for(int i = 0; i < N; i++){
int x = (diam + getD(p1, i) - getD(p2, i)) / 2;
if(x < min(ans, diam - ans)) lSize++;
else if(x == min(ans, diam - ans)) lMid.push_back(i);
else if(x == max(ans, diam - ans)) rMid.push_back(i);
else rSize++;
}
if(sub <= 4){
if(lSize > N / 2 || rSize > N / 2 || lMid.size() > N / 2 || rMid.size() > N / 2) return -ans;
return ans;
}
if(lSize > N / 2 || rSize > N / 2) return -ans;
else if(lMid.size() > N / 2){
stack<int> pilha;
for(int i = 0; i < lMid.size(); i++){
if(pilha.empty()) pilha.push(lMid[i]);
else{
int aux = getD(p1, pilha.top());
int x = (aux + getD(p1, lMid[i]) - getD(pilha.top(), lMid[i])) / 2;
if(x == min(ans, diam - ans)) pilha.pop();
else pilha.push(lMid[i]);
}
}
if(pilha.empty()) return ans;
int k = pilha.top();
int cnt = 0;
for(int i = 0; i < lMid.size(); i++){
int aux = getD(p1, k);
int x = (aux + getD(p1, lMid[i]) - getD(k, lMid[i])) / 2;
if(x > min(ans, diam - ans)) cnt++;
}
if(cnt > N / 2) return -ans;
return ans;
}
else if(rMid.size() > N / 2){
stack<int> pilha;
for(int i = 0; i < rMid.size(); i++){
if(pilha.empty()) pilha.push(rMid[i]);
else{
int aux = getD(p1, pilha.top());
int x = (aux + getD(p1, rMid[i]) - getD(pilha.top(), rMid[i])) / 2;
if(x == max(ans, diam - ans)) pilha.pop();
else pilha.push(rMid[i]);
}
}
if(pilha.empty()) return ans;
int k = pilha.top();
int cnt = 0;
for(int i = 0; i < rMid.size(); i++){
int aux = getD(p1, k);
int x = (aux + getD(p1, rMid[i]) - getD(k, rMid[i])) / 2;
if(x > max(ans, diam - ans)) cnt++;
}
if(cnt > N / 2) return -ans;
return ans;
}
return ans;
}
