#include "combo.h"
#include<bits/stdc++.h>
using namespace std;
std::string guess_sequence(int N) {
string s = "";
vector<char> c{'A', 'B', 'X', 'Y'};
multiset<char> ms;
bool f = 0;
char x;
if (press("AB")) {
if (press("A")) x = 'A';
else x = 'B';
} else {
if (press("X")) x = 'X';
else x = 'Y';
}
s = string(1, x);
auto pos = find(c.begin(), c.end(), x);
c.erase(pos, pos + 1);
auto get = [&] (char x) {
return string(1, x);
};
vector<string> cs{get(c[0]), get(c[1]) + get(c[0]), get(c[1]) + get(c[1]), get(c[1]) + get(c[2])};
for (int i = 2; i < N; i++) {
string p = "";
for (auto &e: cs) p += s + e;
int k = press(p);
if (k == i) s.push_back(c[0]);
else if (k == i + 1) s.push_back(c[1]);
else s.push_back(c[2]);
}
if (N != 1) {
ms.clear();
for (auto &e: c) ms.emplace(e);
f = 0;
while (ms.size() > 1) {
char e = *ms.begin(); ms.erase(ms.begin());
string p = s; p.push_back(e);
if (press(p) == N) {x = e; f = 1; break;}
}
if (!f) x = *ms.begin();
s.push_back(x);
}
return s;
}
