#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
char getFirst(){
if(press("AB")){
if(press("A")) return 'A';
return 'B';
}
if(press("X")) return 'X';
return 'Y';
}
std::string guess_sequence(int N) {
char beg=getFirst();
string ans="", list="ABXY", choice="";
ans.push_back(beg);
for(char c:list){
if(c==beg) continue;
choice.push_back(c);
}
if(N==1) return ans;
for(int i=1;i<N-1;i++){
string query="";
for(int i=0;i<3;i++){
query+=ans;
query+=choice[0];
query+=choice[i];
}
query+=ans;
query+=choice[1];
int sz=ans.size(), ask=press(query);
if(ask==sz+2) ans.push_back(choice[0]);
else if(ask==sz+1) ans.push_back(choice[1]);
else ans.push_back(choice[2]);
}
int sz=ans.size();
for(int i=0;i<3;i++){
if(press(ans+choice[i])==sz+1){
ans.push_back(choice[i]);
return ans;
}
}
ans.push_back(choice[2]);
return ans;
}
