#include "combo.h"
#include <vector>
#include <iostream>
using namespace std;
string guess_sequence(int N) {
char first;
if(press("AB")){
if(press("A")){
first = 'A';
}else{
first = 'B';
}
}else{
if(press("X")){
first = 'X';
}else{
first = 'Y';
}
}
vector<char> valid;
if(first != 'A') valid.push_back('A');
if(first != 'B') valid.push_back('B');
if(first != 'X') valid.push_back('X');
if(first != 'Y') valid.push_back('Y');
string S;
S += first;
for(int i = 1;i < N - 1;i++){
string q = (S + valid[0]) + (S + valid[1] + valid[0]) + (S + valid[1] + valid[1]) + (S + valid[1] + valid[2]);
int ans = press(q);
if(ans == i+1){
S += valid[0];
}else if(ans == i+2){
S += valid[1];
}else{
S += valid[2];
}
}
if(press(S + valid[0]) == N){
S += valid[0];
}else if(press(S + valid[1]) == N){
S += valid[1];
}else{
S += valid[2];
}
return S;
}
