#include "highway.h"
#include <bits/stdc++.h>
using namespace std;
void _7pts(int n, int b, int d) {
int l=0, r=n-2;
vector<int> scuza(n-1,1), paiu;
while (l<r) {
paiu = scuza;
int mid=(l+r)/2;
for (int i=l; i<=mid; ++i) paiu[i]=0;
int x=ask(paiu);
if (x<b*d) r=mid;
else l=mid+1;
}
//cout<<r<<' '<<r+d<<'\n';
answer(r,r+d);
}
void find_pair(int n, vector<int>u, vector<int> v, int a, int b) {
int m=u.size();
vector<int> paiu(m,1);
int dist=ask(paiu)/b;
vector<vector<pair<int,int>>> adj(n);
for (int i=0; i<m; ++i) {
adj[u[i]].push_back({v[i],i});
adj[v[i]].push_back({u[i],i});
}
int foo=1; for (int i=0; i<m; ++i) foo&=(u[i]+1==v[i]);
if (foo) {
_7pts(n,b,dist);
return;
}
queue<int> q;
q.push(0);
vector<int> d(n,0);
vector<int> D;
vector<int> vis(n,0); vis[0]=1;
while (!q.empty()) {
int u=q.front(); q.pop();
for (auto it:adj[u]) {
int v=it.first;
if (!vis[v]) {
d[v]=d[u]+1;
q.push(v);
vis[v]=1;
}
}
}
for (int i=0; i<n; ++i) {
if (d[i]==dist) D.push_back(i);
}
int l=0, r=D.size()-1;
vector<int> scuza(m,1);
while (l<r) {
int mid=(l+r+1)/2;
paiu=scuza;
for (int i=l; i<mid; ++i) {
for (auto it:adj[D[i]]) {
paiu[it.second]=0;
}
}
int x=ask(paiu);
if (x<dist*b) r=mid-1;
else l=mid;
}
answer(0,D[r]);
}
