#include <bits/stdc++.h>
#include "combo.h"
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define all(X) X.begin(), X.end()
#define allr(X) X.rbegin(), X.rend()
#define pb push_back
#define endl '\n'
using namespace std;
using namespace __gnu_pbds;
int press(string p);
string guess_sequence(int n){
string res, s = "ABXY";
for(ll i = 0; i < 4; i++){
if(press(string(1, s[i])) == 1){
res = s[i];
s.erase(s.begin() + i);
break;
}
}
for(ll i = 1; i < n; i++){
string temp = res + s[0] + res + s[1] + res + s[2];
ll cur = press(temp);
if(cur == res.size() + 1) res += s[0];
else if(cur == 2 * (res.size() + 1)) res += s[1];
else res += s[2];
}
return res;
}
