#include "combo.h"
#include <bits/stdc++.h>
std::string guess_sequence(int N) {
using namespace std;
vector<string> ch = {"A", "B", "X", "Y"};
int total = 0;
auto guess = [&](string p) {
total++;
return press(p);
};
if (N == 1) {
for (int i = 0; i < 4; i++) {
int coins = guess(ch[i]);
if (coins == 1) {
return ch[i];
}
}
}
auto find_fst = [&]() {
string p = "AB";
int coins = guess(p);
if (coins == 0) {
p = "X";
coins = guess(p);
return (coins == 1 ? "X" : "Y");
} else {
p = "A";
coins = guess(p);
return (coins == 1 ? "A" : "B");
}
};
string fst = find_fst();
vector<string> len1 = {};
vector<string> len2 = {};
for (auto c : ch) {
if (c != fst) len1.push_back(c);
}
for (int i = 0; i < 3; i++) {
len2.push_back(len1[1] + len1[i]);
}
string ans = fst;
auto build = [&]() {
string tmp = ans;
tmp += len1[0];
for (auto x : len2) {
tmp += (ans + x);
}
assert((int) tmp.size() <= 4 * N);
return tmp;
};
for (int i = 1; i <= N - 2; i++) {
string p = build();
int coins = guess(p);
if (coins == i) {
ans += len1[2];
} else if (coins == i + 1) {
ans += len1[0];
} else {
ans += len1[1];
}
}
for (int i = N - 1; i < N; i++) {
bool found = false;
for (int j = 0; j < 2; j++) {
string tmp = ans + len1[j];
int coins = guess(tmp);
if (coins == i + 1) {
found = true;
ans += len1[j];
break;
}
}
if (!found) {
ans += len1[2];
}
}
cerr << total << '\n';
assert(total <= N + 2);
return ans;
}
