#include "highway.h"
#ifndef EVAL
#include "grader.cpp"
#endif // EVAL
#include <bits/stdc++.h>
using namespace std;
#define lol long long
#define pii pair<int,int>
#define OK puts("OK");
#define NO puts("NO");
#define YES puts("YES");
#define fr first
#define sc second
#define ret return
#define scanl(a) scanf("%lld",&a);
#define scanll(a,b) scanf("%lld %lld",&a, &b);
#define scanlll(a,b,c) scanf("%lld %lld %lld",&a,&b,&c);
#define scan1(a) scanf("%d",&a);
#define scan2(a,b) scanf("%d %d",&a, &b);
#define scan3(a,b,c) scanf("%d %d %d",&a,&b,&c);
#define all(s) s.begin(),s.end()
#define allr(s) s.rbegin(),s.rend()
#define pb push_back
#define sz(v) (int)v.size()
#define endi puts("");
#define eps 1e-12
const int NN = 1e5+12,INF=1e9+7;
bool vis[NN],may[NN];
vector <pii> g[NN];
int cost[NN];
void find_pair(int N, vector<int> U, vector<int> V, int A, int B) {
int m = U.size(),i;
vector <int> w;
vector <pii> q,e;
for (i=0;i<m;++i){
w.pb(0);
g[U[i]].pb({V[i],i});
g[V[i]].pb({U[i],i});
}
int star,cnt = 1,h=0,ans = ask(w),dist = ans/A;
{
int l = 0,r = m-1;
while (r-l>0){
int m = l+r>>1;
for (i=m+1;i<=r;++i){
w[U[i]] = 1;
}
int asd = ask(w);
if (asd != ans){
l = m+1;
}
else {
r = m;
}
for (i=m+1;i<=r;++i){
w[U[i]] = 0;
}
}
star = U[l];
}
vector <int> v;
v.pb(star);
vis[star]=1;
while (h < v.size()){
int x = v[h++];
for (auto to: g[x]){
if (vis[to.fr] == 0){
q.pb({to.sc,to.fr});
vis[to.fr] = 1;
v.pb(to.fr);
}
}
}v.clear();
int aa = ans;
int l = 0, r = q.size()-1;
while (r - l > 0){
int m = l+r>>1,f=0;
for (i=m+1;i<=r;++i){
w[q[i].fr] = 1;
}
int asd = ask(w);
if (asd != ans){
l = m+1;
}
else {
r = m;
}
for (i=m;i<=r;++i){
w[q[i].fr] = 0;
}
}
int s = q[l].sc;
for (i=0;i<N;++i)vis[i]=0;
v.pb(s);
vis[s]=1;
h=0;
while (h < v.size()){
int x = v[h++];
for (auto to: g[x]){
if (vis[to.fr] == 0){
e.pb({to.sc,to.fr});
vis[to.fr] = 1;
v.pb(to.fr);
}
}
}
int t;
{
int l = 0, r = e.size()-1;
while (r - l > 0){
int m = l+r>>1,f=0;
for (i=m+1;i<=r;++i){
w[e[i].fr] = 1;
}
int asd = ask(w);
if (asd != ans){
l = m+1;
}
else {
r = m;
}
for (i=m;i<=r;++i){
w[e[i].fr] = 0;
}
}
t = e[l].sc;
}
answer(s,t);
}
