#include <bits/stdc++.h>
using namespace std;
#define ll long long
const ll mmod = 998244353;
#define vl vector<long long>
#define vll vector<vector<long long>>
#define pl pair<long long, long long>
#define vb vector<bool>
#include "combo.h"
string guess_sequence(int N){
string z = "ABXY";
ll i = 3;
ll c = press("AB");
if (c >= 1){
if (press("B") == 1){
i = 1;
}
else{
i = 0;
}
}
else{
if (press("X") == 1){
i = 2;
}
}
swap(z[i], z[0]);
string s(1, z[0]);
for (ll i = 1; i < N-1; i++){
string ns = s;
string ans = ns + z[1] + ns + z[2] + z[1] + ns + z[2] + z[2] + ns + z[2] + z[3];
ll c = press(ans);
if (c == s.size()){
s += z[3];
}
else if (c == s.size()+1){
s += z[1];
}
else{
s += z[2];
}
}
if (N > 1){
if (press(s + z[1] + s + z[2]) == N){
if (press(s + z[1]) == N){
s += z[1];
}
else{
s += z[2];
}
}
else{
s+=z[3];
}
}
return s;
}
