#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
string guess_sequence(int n) {
string ans = "";
if (press("AB")) {
ans += press("A") ? "A" : "B";
}
else {
ans += press("X") ? "X" : "Y";
}
if (n == 1) {
return ans;
}
vector<char> v;
if (ans[0] != 'A') v.push_back('A');
if (ans[0] != 'B') v.push_back('B');
if (ans[0] != 'X') v.push_back('X');
if (ans[0] != 'Y') v.push_back('Y');
for (int i=1 ; i<n-1 ; i++) {
string tmp = "";
for (char c : v) {
tmp += ans + v[0] + c;
}
tmp += ans + v[1];
ans += v[i - press(tmp) + 2];
}
if (press(ans + v[0]) == n) {
return ans + v[0];
}
else if (press(ans + v[1])) {
return ans + v[1];
}
else {
return ans + v[2];
}
}
