#include <bits/stdc++.h>
#include "combo.h"
using namespace std;
string guess_sequence(int N) {
string sol;
int ok = press("AB");
if(ok) {
int first = press("A");
if(first)
sol = "A";
else
sol = "B";
}
else {
int first = press("X");
if(first)
sol = "X";
else
sol = "Y";
}
string mask = "";
for(const char &ch : "ABXY")
if(ch != sol[0])
mask += ch;
if(N == 1)
return sol;
for(int i = 2; i < N; ++i) {
string ask = sol + mask[0] + sol + mask[1] + mask[0] + sol + mask[1] + mask[1] + sol + mask[1] + mask[2];
int lg = press(ask);
if(lg == i)
sol += mask[0];
else
if(lg == i + 1)
sol += mask[1];
else
sol += mask[2];
}
if(press(sol + mask[0]) == N)
return sol + mask[0];
if(press(sol + mask[1]) == N)
return sol + mask[1];
return sol + mask[2];
}
