#include "combo.h"
#include<bits/stdc++.h>
using namespace std;
string guess_sequence(int n) {
int a=press("AB");
string curs,ads[8];
vector<char>v;
v.push_back('A');
v.push_back('B');
v.push_back('X');
v.push_back('Y');
if(a!=0){
int b=press("A");
if(b==1) curs="A";
else curs="B";
}
else{
int b=press("X");
if(b==1) curs="X";
else curs="Y";
}
if(n==1) return curs;
auto it=lower_bound(v.begin(),v.end(),curs[0]);
v.erase(it);
ads[0]="";
ads[0]+=v[1];
ads[1]="";
ads[1]+=v[2];
ads[2]=ads[1];
ads[3]=ads[1];
ads[1]+=v[0];
ads[2]+=v[1];
ads[3]+=v[2];
// cout<<ads[0]<<' '<<ads[1]<<' '<<ads[2]<<' '<<ads[3]<<"\n";
for(int i=2;i<=n-1;i++){
string ask="";
for(int i=0;i<4;i++) ask+=curs,ask+=ads[i];
int nn=press(ask);
if(nn==i-1) curs+=v[0];
else if(nn==i) curs+=v[1];
else curs+=v[2];
}
a=press(curs+v[0]);
if(a==n) return curs+v[0];
a=press(curs+v[1]);
if(a==n) return curs+v[1];
else return curs+v[2];
// cout<<curs;
}
