#include <iostream>
#include <algorithm>
#include <vector>
#include <random>
#include <chrono>
#include <set>
#include <map>
#include <stack>
#include <functional>
#include <iomanip>
#include <queue>
#include <cassert>
#include <complex>
#include <cstring>
#include <memory>
#include <bitset>
#include <sstream>
#include <cmath>
#include <numeric>
#include <numbers>
#include <fstream>
#include "combo.h"
using namespace std;
#ifndef template
#ifndef define
#define ll long long
#define ld long double
#define pl pair<ll, ll>
#define pi pair<int, int>
#define nl cout << '\n';
#define x first
#define y second
#define cbit(x) __builtin_popcountll(x)
#define uid(a, b) uniform_int_distribution<ll>(a, b)(rng)
#define siz(x) (int)x.size()
#endif
#ifndef print
void print(size_t x) {cout << x << ' ';}
void print(int x) {cout << x << ' ';}
void print(long long x) {cout << x << ' ';}
void print(float x) {cout << x << ' ';}
void print(long double x) {cout << x << ' ';}
void print(char x) {cout << x << ' ';}
void print(const char* x) {cout << x << ' ';}
void print(bool x) {cout << x << ' ';}
void print(string &x) {cout << x << ' ';}
template<typename T, typename V>
void print(pair<T, V> &p) {print(p.x); print(p.y);}
template<typename T>
void print(vector<T> v) {for (int i = 0; i < v.size(); i++) print(v[i]);}
template<typename T>
void print(vector<vector<T>> v) {
for (int i = 0; i < v.size(); i++){
for (int j = 0; j < v[i].size(); j++)
print(v[i][j]);
nl;
}
}
template <typename T, typename... V>
void print(T t, V&&... v) {print(t); print(v...);}
#endif
#ifndef read
void read(int &x) {cin >> x;}
void read(long long &x) {cin >> x;}
void read(unsigned &x) {cin >> x;}
void read(unsigned long long &x) {cin >> x;}
void read(float &x) {cin >> x;}
void read(long double &x) {cin >> x;}
void read(char &x) {cin >> x;}
void read(string &x) {cin >> x;}
void read(bool &x) {cin >> x;}
template<typename T>
void read(vector<T> &v) {
for (int i = 0; i < v.size(); i++)
read(v[i]);
}
template <typename T, typename... V>
void read(T &t, V&... v) {read(t); read(v...);}
#endif
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
template<class T> bool maxi(T& a, const T& b) {
return a < b ? a = b, 1 : 0;
}
template<class T> bool mini(T& a, const T& b) {
return a > b ? a = b, 1 : 0;
}
template<class... Args>
auto vec(size_t n, Args&&... args) {
if constexpr(sizeof...(args) == 1)
return vector(n, args...);
else
return vector(n, vec(args...));
}
#endif
using namespace std;
const ll inf = 1e15;
const ll def = 2001;
const ll mod = 998244353;
// string s;
// int press(string p){
// map<string, int> mp;
// for (int i = 0; i < p.size(); i++) for (int j = 0; j < p.size() - i; j++)
// mp[p.substr(i, j + 1)] = 1;
// int res = 0;
// for (int i = 0; i < s.size(); i++){
// if (mp.count(s.substr(0, i + 1)))
// res = i + 1;
// }
// print("Asked:", p, "Answer", res); nl;
// return res;
// }
char c[4] = {'A', 'B', 'X', 'Y'};
string guess_sequence(int n){
string res = "#";
if (n == 1){
for (int i = 0; i < 3; i++){
if (press(string{c[i]}))
res = string{c[i]};
}
if (res == "#")
res = "Y";
return res;
}
else{
int val = press("AB");
if (val == 2)
res = "A";
else if (val == 1){
val = press("A");
if (val)
res = "A";
else
res = "B";
}
else{
val = press("X");
if (val)
res = "X";
else
res = "Y";
}
}
vector<char> d;
for (int i = 0; i < 4; i++){
if (c[i] == res[0])
continue;
d.push_back(c[i]);
}
for (int i = 1; i < n; i++){
string p = "";
char nxt;
if (i == n - 1){
p += res; p += d[0];
p += res; p += d[1];
int val = press(p);
if (val == res.size() + 1){
p = res; p += d[0];
val = press(p);
if (val == res.size() + 1)
nxt = d[0];
else
nxt = d[1];
}
else
nxt = d[2];
}
else{
p += res; p += d[0];
p += res; p += d[1]; p += d[0];
p += res; p += d[1]; p += d[1];
p += res; p += d[1]; p += d[2];
int val = press(p);
if (val == res.size())
nxt = d[2];
else if (val == res.size() + 1)
nxt = d[0];
else
nxt = d[1];
}
res += nxt;
}
return res;
}
void solve(){
// read(s);
// cout << guess_sequence(s.size());
}
/*
10 4
6
*/
