#include "highway.h"
#include <bits/stdc++.h>
using namespace std;
template<class A> using v=vector<A>;
typedef v<int> vi;
typedef long long ll;
#define sz(S) (int)(S).size()
#define pb push_back
#define get4(a,b,c,d,...) d
#define lp3(x,a,b) for(int x=(a);x<(b);x++)
#define lp2(x,a) lp3(x,0,a)
#define lp1(a) lp2(loopvar,a)
#define lp(x...) get4(x,lp3,lp2,lp1,0)(x)
#define trv(x,S) for(auto& x:(S))
const int mx=200100;
int n,m;
int slct[mx];
void find_pair(int N, vi U, vi V, int A, int B)
{
n=N;
m=sz(U);
vi w(m);
lp(i,m) w[i]=0;
ll ans1=ask(w);
ll ans2;
do
{
lp(i,n) slct[i]=rand()%2;
lp(i,m) w[i]=(slct[U[i]]!=slct[V[i]]);
ans2=ask(w);
}
while(((ans2-ans1)/(B-A))%2==0);
vi sides[2];
lp(i,n) sides[slct[i]].pb(i);
lp(dim,2)
{
while(sz(sides[dim])>1)
{
int md=sz(sides[dim])/2;
lp(i,n) slct[i]=0;
lp(i,md) slct[sides[dim][i]]=true;
lp(i,m) w[i]=(slct[U[i]]!=slct[V[i]]);
ans2=ask(w);
if(((ans2-ans1)/(B-A))%2==0) sides[dim].erase(sides[dim].begin(),sides[dim].begin()+md);
else sides[dim].resize(md);
}
}
answer(sides[0][0],sides[1][0]);
}
