#include "bits/stdc++.h"
#include "combo.h"
using namespace std;
string guess_sequence(int N)
{
string S, s = "ABXY";
if (press("AB"))
{
if (press("A"))
S = "A";
else
S = "B";
}
else
{
if (press("X"))
S = "X";
else
S = "Y";
}
int j = 0;
while (S[0] != s[j])
j++;
s.erase(s.begin() + j);
while (S.size() < N)
{
string T = (S + s[0]) + (S + s[1] + s[0]) + (S + s[1] + s[1]) + (S + s[1] + s[2]);
int x = press(T);
if (x == S.size())
S += s[2];
else if (x == S.size() + 1)
S += s[0];
else
S += s[1];
}
return S;
}
