#include <bits/stdc++.h>
using namespace std;
vector<char> buttons={'A','B','X','Y'};
int press(string p);
string guess_sequence(int N){
string soFar;
vector<char> av;
if (press("AB")>0){
if (press("A")==1){
soFar="A";
} else {
soFar="B";
}
} else {
if (press("X")==1){
soFar="X";
} else {
soFar="Y";
}
}
if (N==1) return soFar;
for (int i=0;i<4;i++){
if (buttons[i]==soFar[0]) continue;
av.push_back(buttons[i]);
}
while (soFar.size()<N-1){
int size=soFar.size();
string pat=(soFar+av[0]+av[0]) + (soFar+av[0]+av[1]) + (soFar+av[0]+av[2]) + (soFar+av[1]);
int wynik=press(pat);
if (wynik==size+2) soFar.push_back(av[0]);
else if (wynik==size+1) soFar.push_back(av[1]);
else soFar.push_back(av[2]);
}
if (press(soFar+av[0])==N){
soFar.push_back(av[0]);
} else if (press(soFar+av[1])==N){
soFar.push_back(av[1]);
} else {
soFar.push_back(av[2]);
}
return soFar;
}
