#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);
string a, b, c, d;
a += s[0];
b += s[1];
c += s[1];
d += s[1];
b += s[0];
c += s[1];
d += s[2];
while (S.size() < N - 1)
{
string T = (S + a) + (S + b) + (S + c) + (S + d);
// cout << T;
int x = press(T);
if (x == S.size())
S += s[2];
else if (x == S.size() + 1)
S += s[0];
else
S += s[1];
}
a = b = c = S;
a += s[0];
b += s[1];
c += s[2];
if (press(a) == N)
return a;
else if (press(b) == N)
return b;
else
return c;
}
