#include <bits/stdc++.h>
#include "combo.h"
using namespace std;
std::string guess_sequence(int N)
{
int k = press("AB");
//debug(k);
char first_letter = '[';
if(k == 2){
first_letter = 'A';
}
else if(k == 1){
if(press("B"))first_letter = 'B';//ABBXXYXYXYXYXYXYBBBBBBs
else first_letter = 'A';
}
else{
if(press("X"))first_letter = 'X';
else first_letter = 'Y';
}
//debug(first_letter);
string ss;
if(first_letter != 'A' )ss.push_back('A');
if(first_letter != 'B' )ss.push_back('B');
if(first_letter != 'X' )ss.push_back('X');
if(first_letter != 'Y' )ss.push_back('Y');
//debug(ss);
string ans;
ans.push_back(first_letter);
for(int i = 1; i < N;i++){
int x = ans.size();
if(x+2 > N)break;
k = press(ans+ss[0]+ss[0]+ans+ss[0]+ss[1]+ans+ss[0]+ss[2]+ans+ss[1]);
if(k == x+2){
ans.push_back(ss[0]);
}
else if(k == x+1)ans.push_back(ss[1]);
else ans.push_back(ss[2]);
}
int x = ans.size();
k = press(ans+ss[1]);
if(k > x)ans.push_back(ss[1]);
else if(press(ans+ss[2]) == x+1)ans.push_back(ss[2]);
else ans.push_back(ss[0]);
return ans;
}
