#include <bits/stdc++.h>
#include "combo.h"
#define debug
#define lp(i,a,b) for(int i=a;i<b;i++)
#define pii pair<int,int>
#define ll long long
#define ff first
#define ss second
#define pb push_back
#define mk make_pair
const int MAXN = 2e3+10 ;
using namespace std ;
int n ;
string guess_sequence(int n)
{
string p ;
int firstLetter ;
char c[4] = {'A' , 'B' , 'X' , 'Y'} ;
p.resize( n ) ;
//Find first letter
string p1 = "AB" , p2 = "XY" ;
if( press(p1) != 0 )
{
firstLetter = 0 ;
p1 = "B" ;
if( press(p1) != 0 ) firstLetter = 1 ;
}
else
{
firstLetter = 2 ;
p2 = "Y" ;
if( press(p2) != 0 ) firstLetter = 3 ;
}
p = c[firstLetter] ;
swap( c[firstLetter] , c[0] ) ;
lp(i,2,n)
{
string aux = p + c[2] ;
lp(j,1,4) aux = aux + p + c[1] + c[j] ;
int newVal = press(aux) ;
if(newVal == i) p += c[2] ;
else if( newVal == i+1 ) p += c[1] ;
else p += c[3] ;
}
string aux = p + c[1] ;
if( press(aux) == n ) return aux ;
aux = p + c[2] ;
if(press(aux) == n) return aux ;
p += c[3] ;
return p ;
}
