#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
string guess_sequence(int N) {
string S = "";
if (press("AB")) S+=(press("A") ? 'A' : 'B');
else S+=(press("X") ? 'X' : 'Y');
vector<char> c;
for (auto x : {'A', 'B', 'X', 'Y'}) {
if (x != S[0]) c.push_back(x);
}
for (int i = 1; i < N-1; ++i) {
int val = press(S+c[0]+S+c[1]+c[0]+S+c[1]+c[1]+S+c[1]+c[2]);
if (val == i+1) S+=c[0];
else if (val == i+2) S+=c[1];
else S+=c[2];
}
if ((int)S.size() < N) {
if (press(S+c[0]+S+c[1]) == N) S+=(press(S+c[0]) == N ? c[0] : c[1]);
else S+=c[2];
}
return S;
}
