#include<iostream>
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <string>
#include "combo.h"
using namespace std;
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 == 1) cout<<ans1+ans2<<" "<<press(ans1+ans2)<<endl;
int x = press(ans1+ans2);
if(x > i){
i++;
ans+="AB";
}
else if(x == 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;
}
