#include "bits/stdc++.h"
#include "combo.h"
// #include "ext/pb_ds/assoc_container.hpp"
// #include "ext/pb_ds/tree_policy.hpp"
// using namespace __gnu_pbds;
using namespace std;
typedef long long int ll;
// #define int long long
#define pb push_back
#define fi first
#define se second
#define fr(i, a, b) for(int i = a; i <= b; i++)
#define all(x) x.begin(), x.end()
#define IO ios :: sync_with_stdio(0), cin.tie(0), cout.tie(0)
#define pii pair<int,int>
#define sz(x) (int)x.size()
const int mod = 998244353;
const int mod1 = 998244353;
typedef long double f80;
#ifndef LOCAL
#pragma GCC optimize ("Ofast")
#define endl '\n'
#endif
// template<typename T>
// using ordered_set = tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int rand(int l, int r){
uniform_int_distribution<int> uid(l, r);
return uid(rng);
}
ll pwr(ll a,ll b){
a %= mod;
int ans = 1;
while(b){
if(b & 1) ans = (ans * a) % mod;
a = (a * a) % mod;
b >>= 1;
}
return ans;
}
string to_string(string s) {
return '"' + s + '"';
}
string to_string(const char* s) {
return to_string((string) s);
}
string to_string(bool b) {
return (b ? "true" : "false");
}
template <typename A, typename B>
string to_string(pair<A, B> p) {
return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
template <typename A>
string to_string(A v) {
bool first = true;
string res = "{";
for (const auto &x : v) {
if (!first) {
res += ", ";
}
first = false;
res += to_string(x);
}
res += "}";
return res;
}
void debug_out() { cerr << endl; }
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
cerr << " " << to_string(H);
debug_out(T...);
}
#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif
string guess_sequence(int n){
string s = "";
if(press("AB")){
if(press("A"))
s += 'A';
else
s += 'B';
}
else{
if(press("X")){
s += 'X';
}
else{
s += 'Y';
}
}
vector<char> v;
if(s[0] != 'A'){
v.pb('A');
}
if(s[0] != 'B'){
v.pb('B');
}
if(s[0] != 'X'){
v.pb('X');
}
if(s[0] != 'Y'){
v.pb('Y');
}
for(int i = 2; i < n; i++){
string ss = s;
ss += v[0];
ss += v[0];
ss += s;
ss += v[0];
ss += v[1];
ss += s;
ss += v[0];
ss += v[2];
ss += s;
ss += v[1];
int val = press(ss);
if(val == sz(s)){
s += v[2];
}
else if(val == sz(s) + 1){
s += v[1];
}
else{
s += v[0];
}
}
for(char ch : v){
string ss = s;
ss += ch;
if(press(ss) == sz(s) + 1){
s += ch;
break;
}
}
return s;
}
