#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
string guess_sequence(int n) {
string s = "";
if (press("AB") > 0) {
if (press("A")) {
s += "A";
} else {
s += "B";
}
} else {
if (press("X")) {
s += "X";
} else {
s += "Y";
}
}
if (n == 1) return s;
for (int i = 1; i < n - 1; ++i) {
vector<char> c;
for (auto ch : {'A', 'B', 'X', 'Y'}) {
if (ch != s[0]) {
c.push_back(ch);
}
}
string query = s + c[0] + s + c[1] + c[0] + s + c[1] + c[1] + s + c[1] + c[2];
int x = press(query);
if (x == i) {
s += c[2];
} else if (x == i + 1) {
s += c[0];
} else {
s += c[1];
}
}
if (press(s + "A" + s + "B") == n) {
if (press(s + "A") == n) {
s += "A";
} else {
s += "B";
}
} else {
if (press(s + "X") == n) {
s += "X";
} else {
s += "Y";
}
}
return s;
}
