#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()Ñ,s.rend()
#define pb push_back
#define sz(v) (int)v.size()
#define endi puts("");
#define eps 1e-12
const int NN = 3e5+12,INF=1e9+7;
bool vis[NN],may[100001];
vector <int> g[NN];
void find_pair(int N, vector<int> U, vector<int> V, int A, int B) {
int n = U.size();
vector<int> w(n);
int i,j;
for (i = 0; i < n; ++i){
g[U[i]].pb(V[i]);
g[V[i]].pb(U[i]);
w[i] = 0;
}
long long ans = ask(w),l=0,r=0;
for (i=1;i<n;++i){
w[i] = 1;
int x = ask(w);
if (x > ans){
ans = x;
may[U[i]]=1;
may[V[i]]=1;
}
else {
w[i] = 0;
}
}
bool f=1;
vis[l]=1;
vis[r]=1;
while (f){
f=0;
for (int to : g[l]){
if (vis[to] == 0 && may[to] == 1){
l = to;
vis[l]= 1;
f=1;
break;
}
}
}
answer(l, r);
}
