#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
using vi = vector<int>;
using ii = pair<int, int>;
using vii = vector<ii>;
using i64 = int64_t;
using vl = vector<i64>;
using ll = pair<i64, i64>;
using vll = vector<ll>;
constexpr int iINF = numeric_limits<int>::max();
constexpr i64 lINF = numeric_limits<i64>::max();
#define RANGE(x) begin(x), end(x)
template <typename... T>
void DBG(T&&... args) {
((cerr << args << ' '), ...) << '\n';
}
template <typename T>
ostream &operator<<(ostream &out, const vector<T> &vec) {
out << '{';
for (size_t i = 0; i < vec.size()-1; ++i)
out << vec[i] << ", ";
out << vec.back() << '}';
return out;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &out, const pair<T1, T2> &pr) {
out << '(' << pr.first << ", " << pr.second << ')';
return out;
}
std::string guess_sequence(int N) {
vector<char> chars{'A', 'B', 'X'};
string p;
for (char c : chars) {
if (press(string(1, c))) {
p = string(1, c);
break;
}
}
if (p.empty()) {
p = string(1, 'Y');
} else {
chars.erase(find(RANGE(chars), p[0]));
chars.push_back('Y');
}
DBG(p);
for (int i = 1; i < N - 1; ++i) {
string test = p + chars[0];
for (char c : chars) test += p + chars[1] + c;
DBG(p);
DBG(test, test.size());
int coins = press(test);
if (coins == i) {
p += chars[2];
} else if (coins == i+1) {
p += chars[0];
} else if (coins == i+2) {
p += chars[1];
} else {
while (1) new int;
}
}
DBG(p);
string test;
if (press(test = p + chars[0]) == N) return test;
else if (press(test = p + chars[1]) == N) return test;
return p + chars[2];
}
