#pragma GCC optimize("O2")
#pragma GCC target("avx,avx2,fma")
#include "combo.h"
#include <bits/stdc++.h>
#define FOR(i, a, b) for (int i = (a); i <= (b); i++)
#define FOD(i, a, b) for (int i = (a); i >= (b); i--)
#define REP(i, n) for (int i = 0; i < (n); i++)
#define ALL(x) (x).begin(), (x).end()
#define TIME (1.0 * clock() / CLOCKS_PER_SEC)
#define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
using namespace std;
const int MAXN = 2e5 + 5;
string guess_sequence(int N) {
string t = "";
FOR(i, 1, N) {
for (char x : {'A', 'B', 'X', 'Y'}) {
t += x;
if (press(t) == i) break;
t.pop_back();
}
}
return t;
}
