//author: Hakimov Rahimjon
//nickname:
//e-mail: rahimjon0777@gmail.com
#include <bits/stdc++.h>
#include "combo.h"
#define fin(x) freopen(x, "r", stdin)
#define fout(x) freopen(x, "w", stdout)
#define LL long long
#define LD long double
#define pb(x) push_back(x)
#define pf(x) push_front(x)
#define Pb pop_back
#define Pf pop_front
#define fi first
#define se second
using namespace std;
int TN = 1;
/*int press(string p) {
cout << p << "\n";
int x;
cin >> x;
return x;
}
*/
string guess_sequence(int N) {
int cur = 1;
string cr = "";
if (N==0) return "";
vector <char> st;
if (press("A")) {
cr += "A";
st = {'B', 'X', 'Y'};
}
else if (press("B")) {
cr += "B";
st = {'A', 'X', 'Y'};
}
else if (press("X")) {
cr += "X";
st = {'A', 'B', 'Y'};
}
else {
cr += "Y";
st = {'A', 'B', 'X'};
}
for (int i = 0; i < N-1; i++) {
if (press(cr+st[0]) > cur) {
cr += st[0];
cur += 1;
}else if (press(cr+st[1]) > cur) {
cr += st[1];
cur += 1;
}else if (press(cr+st[2]) > cur) {
cr += st[2];
cur += 1;
}else break;
}return cr;
}
/*int solution() {
cout << guess_sequence(20);
return 0;
}
int main() {
//cin >> TN;
//fin("input.txt");fout("output.txt");
for (int i = 0; i < TN; i++) solution();
return 0;
}
*/
