#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
string guess_sequence(int n) {
vector <string> v;
string s = "";
if (!press("X")) v.emplace_back("X");
else s = "X";
if (!press("Y")) v.emplace_back("Y");
else s = "Y";
if (!press("A")) v.emplace_back("A");
else s = "A";
if (v.size() == 2) v.emplace_back("B");
else s = "B";
for (int i = 1; i < n-1; i++) {
string ask = s;
ask += v[0];
for (int i = 0; i < 3; i++) ask += (s + v[1] + v[i]);
int k = press(ask) - s.size();
if (k == 0) s += v[2];
else if (k == 1) s += v[0];
else s += v[1];
}
if (n > 1) {
if (press(s + v[0]) == n) s += v[0];
else if (press(s + v[1]) == n) s += v[1];
else s += v[2];
}
return s;
}
