#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 = "";
string s = "ABXY";
for(ll i = 0; i < 4; i++){
res = s[i];
if(press(res)){
s = s.substr(0, i) + (i != 3 ? s.substr(i + 1, 4 - i) : "");
break;
}
}
for(ll i = 1; i < n; i++){
char a = s[0], b = s[1];
string temp = res + a + res + b;
ll cur = press(temp);
if(cur == res.size() + 1) res += a;
else if(cur == res.size() * 2 + 2) res += b;
else res += s[2];
}
return res;
}
