#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
#define F first
#define S second
#define endl '\n'
#define fastio ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define maxp 22
#define EPS (ld)(1e-18)
#define mod (int)(1e9+7)
/// x = press(string s) for query
string guess_sequence(int N) {
int i,j;
string s="";
char moves[4]={'A','B','X','Y'};
int one,alone,no,both;
int x=press("AB");
if(x==0){
no=0;
alone=1;
x=press("X");
if(x==0){
one=3;
both=2;
}
else{
one=2;
both=3;
}
}
else{
no=2;
alone=3;
x=press("A");
if(x==0){
one=1;
both=0;
}
else{
one=0;
both=1;
}
}
s+=moves[one];
for(i=1;i<N-1;i++){
string p=s+moves[alone];
for(j=0;j<4;j++)
if(j!=one)
p+=s+moves[both]+moves[j];
int x=press(p);
if(x==i)
s+=moves[no];
else if(x==i+1)
s+=moves[alone];
else
s+=moves[both];
}
string p=s+moves[alone]+s+moves[no];
x=press(p);
if(x==N-1)
s+=moves[both];
else{
p=s+moves[alone];
x=press(p);
if(x==N-1)
s+=moves[no];
else
s+=moves[alone];
}
return s;
}
