#include <bits/stdc++.h>
#define fto(i, a, b) for (int i = a; i <= b; ++i)
using namespace std;
int n;
string haha[5] = {"A", "B", "X", "Y"};
int press(string p);
string guess_sequence(int n){
int hoho, hehe = 0;
string tmp = "", G = "";
fto(i, 1, n){
fto(j, 0, 3){
tmp = G + haha[j];
hoho = press(tmp);
fflush(stdout);
if (hehe < hoho){
hehe = hoho;
G = tmp;
break;
}
}
}
return G;
}
// #ifdef LOCALME
// int main() {
// int n; cin >> n;
// cout << guess_sequence(n) << endl;
// return 0;
// }
// #endif
