#include "combo.h"
#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair < int, int > pii;
typedef pair < ll, ll > pll;
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define SZ(x) (int)x.size()
#define Mp make_pair
#define endl "\n"
#define fast_io ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
const int N = 1e6 + 10;
const int LOG = 20;
const ll mod = 1e9 + 7;
const ll inf = 8e18;
string A[4] = {"A", "B", "X", "Y"};
vector < string > vec;
string guess_sequence(int n)
{
mt19937 rng(time(nullptr));
string ans;
shuffle(A, A + 4, rng);
if(press("XY"))
{
if(press("X")) ans = "X";
else ans = "Y";
}
else
{
if(press("B")) ans = "B";
else ans = "A";
}
for(int j = 0; j < 4; j ++)
{
if(ans == A[j]) continue;
vec.push_back(A[j]);
}
for(int i = 1; i < n - 1; i ++)
{
string now2 = ans + vec[2];
string now = ans + vec[1] + now2 + vec[0] + now2 + vec[1] + now2 + vec[2];
ans += vec[press(now) - i];
}
if(n - 1)
{
for(int j = 0; j < 2; j ++)
{
if(press(ans + vec[j]) == n)
{
ans += vec[j];
break;
}
}
if(SZ(ans) == n - 1) ans += vec[2];
}
return ans;
}
