#include "combo.h"
#include "bits/stdc++.h"
using namespace std;
string guess_sequence(int N) {
string p;
vector < char > vc = {'A', 'X', 'B', 'Y'};
if ( press("AB") ) {
if ( press("A") ) {
p += 'A';
vc.erase(vc.begin());
}
else {
p += 'B';
vc.erase(vc.begin() + 2);
}
}
else {
if ( press("X") ) {
p += 'X';
vc.erase(vc.begin() + 1);
}
else {
p += 'Y';
vc.erase(vc.begin() + 3);
}
}
for ( int i = 1; i < N - 1; i++ ) {
string t;
t += p + vc[0];
t += p + vc[1] + vc[0];
t += p + vc[1] + vc[1];
t += p + vc[1] + vc[2];
int sz = p.size(), x = press(t);
if ( x == sz + 1 ) {
p += vc[0];
}
else if ( x == sz + 2 ) {
p += vc[1];
}
else {
p += vc[2];
}
}
string t;
t += p + vc[0];
t += p + vc[1];
if ( press(t) == N ) {
t = p + vc[0];
if ( press(t) == N ) {
p += vc[0];
}
else {
p += vc[1];
}
}
else {
p += vc[2];
}
return p;
}
