#include "combo.h"
#include <bits/stdc++.h>
#define pb push_back
using namespace std;
string guess_sequence(int n) {
string s, ans;
int ret = press("AB");
if (ret == 2) ans += "AB";
else if (ret == 1) {
ret = press("A");
if (ret == 1) ans += "A";
else ans += "B";
} else {
ret = press("X");
if (ret == 1) ans += "X";
else ans += "Y";
}
if (ans.size() == n) return ans;
vector<string> vec;
if (ans[0] != 'A') vec.pb("A");
if (ans[0] != 'B') vec.pb("B");
if (ans[0] != 'X') vec.pb("X");
if (ans[0] != 'Y') vec.pb("Y");
while (ans.size() + 1 < n) {
s = ans + vec[0] + ans + vec[1] + vec[0] + ans + vec[1] + vec[1] + ans + vec[1] + vec[2];
int ret = press(s);
if (ret == (int)ans.size()) ans += vec[2];
if (ret == (int)ans.size() + 1) ans += vec[0];
if (ret == (int)ans.size() + 2) ans += vec[1];
}
if (press(ans + vec[0]) == n) ans += vec[0];
else if (press(ans + vec[1]) == n) ans += vec[1];
else ans += vec[2];
return ans;
}
