#include <bits/stdc++.h>
#pragma GCC optimize("O3")
using namespace std;
#define MAXN 200005
#define FOR(i, n) for (int i = 0; i < n; i++)
#define FORR(j, i, n) for (int i = j; i < n; i++)
#define FORD(i, n) for (int i = n - 1; i >= 0; i--)
#define FOBIR(i, n) for (int i = 1; i <= n; i++)
#define pb push_back
#define mp make_pair
#define endl '\n'
#define DUEHOANG \
ios_base::sync_with_stdio(0); \
cin.tie(NULL); \
cout.tie(NULL)
#define JaydenXia(in, out) \
freopen(in, "r", stdin); \
freopen(out, "w", stdout);
#define long long long
typedef set<int> si;
typedef vector<int> vi;
typedef pair<int, int> pii;
typedef vector<pii> vii;
typedef priority_queue<int> pqi;
typedef stack<int> sti;
typedef queue<int> qi;
typedef deque<int> di;
typedef map<int, int> mii;
#define f first
#define s second
int press(string p);
string guess_sequence(int n)
{
string ans = "";
if(press("AB") >= 1)
{
if(press("A") >= 1) ans += 'A';
else ans += 'B';
}
else if(press("X") >= 1) ans += 'X';
else ans += 'Y';
vector<char> poss;
poss.push_back('A');
poss.push_back('B');
poss.push_back('Y');
poss.push_back('X');
poss.erase(find(poss.begin(), poss.end(), ans[0]));
for(int i = 2; i < n; i++)
{
int next = press(ans + poss[0] + (ans + poss[1] + poss[0] + ans + poss[1] + poss[1] + ans + poss[1] + poss[2]));
if(next < i) ans += poss[2];
else if(next == i) ans += poss[0];
else ans += poss[1];
}
if(n == 1) return ans;
if(press(ans + poss[0]) == n) ans = ans + poss[0];
else if(press(ans + poss[1]) == n) ans = ans + poss[1];
else ans = ans + poss[2];
return ans;
}
