#include "combo.h"
#include <string>
#include <vector>
using namespace std;
string guess_sequence(int N)
{
string res;
if(press("AB") == 1)
{
res = (press("A") == 1 ? "A" : "B");
}
else
{
res = (press("X") == 1 ? "X" : "Y");
}
int pos;
string query;
int query_res;
vector<string> C;
for(string t: {"A", "B", "X", "Y"}) if(t != res) C.push_back(t);
for(pos = 1; pos <= N-2; pos++)
{
query.clear();
query += res + C[0];
query += res + C[1] + C[0];
query += res + C[1] + C[1];
query += res + C[1] + C[2];
query_res = press(query);
if(query_res == 0) res += C[2];
else if(query_res == pos + 1) res += C[0];
else res += C[1];
}
if(press(res + C[0] + res + C[1]) == pos)
{
res += C[2];
pos++;
}
else
{
if(press(res + C[0]) == pos + 1)
{
res += C[0];
pos++;
}
else
{
res += C[1];
pos++;
}
}
return res;
}
