#include <combo.h>
#include<string>
#include <vector>
using namespace std;
#define t press
string guess_sequence(int N)
{
std::string r, p, o = "ABXY";
int i, j, c;
r = t("AB") ? t("A") ? "A" : "B" : t("X") ? "X" : "Y";
if(N==1)return r;
for (i = 0; i < 4; i++)if (o[i] == r[0]){ o.erase(o.begin() + i); break; }
for (int i = 1; i < N - 1; i++)
{
p=r+o[0];for(j=0;j<3;){p+=r+o[1]+o[j++];}
c = t(p);
if (c == i)
r += o[2];
else if (c == i + 1)
r += o[0];
else
r += o[1];
}
r+=o[t(r+o[0]+r+o[1])==N?t(r+o[0])==N?0:1:2];
return r;
}
