#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
//#define int long long
#define pii pair<ll, ll>
#define fi first
#define se second
const ll MAXX = 2e5 + 5, inf = 1e9, mod = 1e9 + 7, block = 320, lim = 16;
//namespace {
//
//constexpr int MAX_N = 2000;
//constexpr int MAX_NUM_MOVES = 8000;
//
//int N;
//std::string S;
//
//int num_moves = 0;
//
//void wrong_answer(const char *MSG) {
// printf("Wrong Answer: %s\n", MSG);
// exit(0);
//}
//
//} // namespace
//
//int press(std::string p) {
// cout << p << ' ' << num_moves << '\n';
// if (++num_moves > MAX_NUM_MOVES) {
// cout << num_moves << '\n';
// wrong_answer("too many moves");
// }
// int len = p.length();
// if (len > 4 * N) {
// wrong_answer("invalid press");
// }
// for (int i = 0; i < len; ++i) {
// if (p[i] != 'A' && p[i] != 'B' && p[i] != 'X' && p[i] != 'Y') {
// wrong_answer("invalid press");
// }
// }
// int coins = 0;
// for (int i = 0, j = 0; i < len; ++i) {
// if (j < N && S[j] == p[i]) {
// ++j;
// } else if (S[0] == p[i]) {
// j = 1;
// } else {
// j = 0;
// }
// coins = std::max(coins, j);
// }
// return coins;
//}
string convert(string &ans, vector <char> &unbanned) {
string t = ans;
t += unbanned[0];
t += unbanned[0];
t += ans;
t += unbanned[0];
t += unbanned[1];
t += ans;
t += unbanned[0];
t += unbanned[2];
t += ans;
t += unbanned[1];
return t;
// ans + (to_string)unbanned[0] + (to_string)unbanned[0] +
// ans + (to_string)unbanned[0] + (to_string)unbanned[1] +
// ans + (to_string)unbanned[0] + (to_string)unbanned[2] +
// ans + (to_string)unbanned[1];
}
map <char, int> mp;
string guess_sequence(int N) {
mp['A'] = 1, mp['B'] = 2, mp['X'] = 3, mp['Y'] = 4;
string ans = "";
int begin = 0;
int t = press("AB");
if (t) {
int t1 = press("A");
if (t1) ans += "A";
else ans += "B";
if (t1) begin = 1;
else begin = 2;
}
else {
int t1 = press("X");
if (t1) ans += "X";
else ans += "Y";
if (t1) begin = 3;
else begin = 4;
}
if ((int)ans.size() == N) return ans;
vector <char> unbanned;
for (auto i : mp) {
if (begin != i.se) unbanned.push_back(i.fi);
// cout << i.fi << ' ';
}
while((int)ans.size() < N - 1) {
string pre = convert(ans, unbanned);
int t = press(pre);
if (t == ans.size()) ans += unbanned[2];
else if (t == ans.size() + 1) ans += unbanned[1];
else if (t == ans.size() + 2) ans += unbanned[0];
}
// for (auto i : unbanned) {
{
string tmp = ans;
tmp += unbanned[0];
int t = press(tmp);
if (t == N) return tmp;
tmp = ans;
tmp += unbanned[1];
t = press(tmp);
if (t == N) return tmp;
tmp = ans;
tmp += unbanned[2];
return tmp;
}
// }
// return ans;
}
//int main() {
// char buffer[MAX_N + 1];
// if (scanf("%s", buffer) != 1) {
// fprintf(stderr, "Error while reading input\n");
// exit(1);
// }
// S = buffer;
// N = S.length();
//
// num_moves = 0;
// std::string answer = guess_sequence(N);
// if (answer != S) {
// wrong_answer("wrong guess");
// exit(0);
// }
// printf("Accepted: %d\n", num_moves);
// return 0;
//}
//
