#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <string>
#include "combo.h"
#include<bits/stdc++.h>
#define INF 1e18
#define fi first
#define se second
#define FOR(i, k, n) for(ll i = k; i <= n; i++)
#define FOR1(i, k, n) for(ll i = k; i >= n; i--)
#define pb push_back
#define fastio ios::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define vi vector<int>
#define pii pair<int, int>
#define vii vector<pii>
#define ll long long
#define vll vector<ll>
#define pll pair<ll, ll>
#define re return 0
#define mii map<int, int>
#define input "chinaflu.inp"
#define output "chinaflu.out"
#define rf freopen(input, "r", stdin); freopen(output, "w", stdout)
using namespace std;
const int maxn = 3e5 + 5;
const int mod = 1e9 + 9;
const int base = 998244353;
void add(int &a, int b)
{
a += b;
if(a >= mod) a -= mod;
if(a < 0) a += mod;
}
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
int rand(int l, int r)
{
return uniform_int_distribution<int>(l, r) (rd);
}
string guess_sequence(int n)
{
string P = "";
int k = press("AB");
if(k)
{
k = press("A");
if(k)
P += 'A';
else
P += 'B';
}
else
{
k = press("X");
if(k)
P += 'X';
else
P += 'Y';
}
n--;
vector<char> vv;
if('A' != P[0])
vv.pb('A');
if('B' != P[0])
vv.pb('B');
if('X' != P[0])
vv.pb('X');
if('Y' != P[0])
vv.pb('Y');
while(true)
{
if(!n)
return P;
if(n == 1)
{
string t = "";
t += vv[0];
k = press(t);
if(k)
{
P += vv[0];
return P;
}
t.clear();
t += vv[1];
k = press(t);
if(k)
{
P += vv[1];
return P;
}
P += vv[2];
return P;
}
string ask = "";
ask += P;
ask += vv[0];
ask += vv[1];
ask += P;
ask += vv[0];
ask += vv[0];
ask += P;
ask += vv[0];
ask += vv[2];
ask += P;
ask += vv[1];
k = press(ask);
int cnt = P.size();
if(k == cnt + 2)
P += vv[0];
if(k == cnt + 1)
P += vv[1];
if(k == cnt)
P += vv[2];
n--;
}
}
