#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
string guess_sequence(int N) {
string known = "";
int gl = press("AB");
string pref;
if (gl>0){
if(press("A"))pref="A";
else pref = "B";
}
else{
if(press("X"))pref="X";
else pref="Y";
}
char first = pref[0];
vector<char> av;
for(auto thing:{'A', 'B', 'X', 'Y'})if(thing!=first)av.push_back(thing);
while(pref.size()<N-1){
int x = press(pref+av[0]+av[0]+pref+av[0]+av[1]+pref+av[0]+av[2]+pref+av[1]);
char c;
if(x>=pref.size()+2)c=av[0];
else if(x>=pref.size()+1)c=av[1];
else c=av[2];
pref.push_back(c);
}
if(pref.size()==N)return pref;
int x = press(pref+av[0]);
if(x==N)return pref+av[0];
x= press(pref+av[1]);
if(x==N)return pref+av[1];
return pref+av[2];
}
