#include "highway.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> p32;
typedef pair<ll,ll> p64;
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define vi vector<int>
#define vp32 vector<p32>
#define fast_cin() ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
#define MOD %1000000007
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template <class T>
using Tree =
tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
//never guess
//never debug without reviewing code
//never try adding ones or substracting them
//only step by step debug when necessay
void find_pair(int N, std::vector<int> U, std::vector<int> V, int A, int B) {
int m = U.size();
ll curxor = 0, curs = 0;
int x = 1, p = 0;
while(x<N){
vi w(m,1);
for(int i = 0; i<m; i++){
if((U[i]&x)^(V[i]&x)) w[i] = 0;
}
curxor+=(ask(w)&1)<<p;
x<<=1;
p++;
}
x = 1, p = 0;
while(x<N){
vi w(m,1);
bool done[N]; memset(done,0,sizeof done);
bool include[N]; memset(include,0,sizeof include);
int mask = (x<<1)-1;
for(int i = 0; i<N; i++){
if(done[i])continue;
if((i&mask)==curs){
include[i] = true;
done[i] = true;
if((i^curxor)<N)
done[i^curxor] = true;
}
}
for(int i = 0; i<m; i++){
if(include[U[i]]^include[V[i]]) w[i] = 0;
}
curs+=(!(ask(w)&1))<<p;
x<<=1;
p++;
}
answer(curs,curs^curxor);
}
