#include "combo.h"
#include<bits/stdc++.h>
using namespace std;
//string S = "ABB";
/*int press(string s){
string x;
for(int i = 1; i<=s.size(); ++i){
x+=S[i-1];
if(!s.find(x)) return i-1;
}
return 0;
}*/
string guess_sequence(int N){
string ans;
for(int i = 1; i<=N; ++i){
string ans1 = ans; string ans2 = ans;
ans1+='A'; ans2+='B';
if(i == 2) cout<<ans1+ans2<<" "<<press(ans1+ans2)<<endl;
if(press(ans1+ans2) == i){
if(press(ans1) == i) ans+='A';
else ans+='B';
}
else{
ans1[i-1] ='X';
if(press(ans1) == i) ans+='X';
else ans+='Y';
}
}
return ans;
}
