#include "combo.h"
#include <bits/stdc++.h>
#include <stdio.h>
#define __Shibae__ signed main()
#define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define fiopen(Path) freopen(Path".INP", "r", stdin); freopen(Path".OUT", "w", stdout);
#define fipen(Path) freopen(Path".INP", "r", stdin);
#define sz(s) (int)s.size()
#define all(x) x.begin(), x.end()
#define maxHeap priority_queue<int>
#define minHeap priority_queue<int, vector<int>, greater<int>>
#define getBit(x, k) (((x) >> (k)) & 1)
#define MASK(i) (1LL << (i))
#define SQR(x) (1LL * ((x) * (x)))
#define db double
#define ld long double
#define ui unsigned int
#define ll long long
#define ii pair<int, int>
#define pli pair<ll, int>
#define pil pair<int, ll>
#define pll pair<ll, ll>
#define fi first
#define se second
#define FOR(i, a, b) for(int i = a, _b = b; i <= _b; i += 1)
#define FOD(i, a, b) for(int i = a, _b = b; i >= _b; i -= 1)
#define REP(i, a) for(int i = 0, _a = a; i < _a; i++)
#define pb push_back
#define fau(u, a) for(auto &u : a)
#define debug return cout << "debug", void();
using namespace std;
const ll mod = 1e9 + 7;
const int INF = 1e9 + 7;
const ll INFLL = (ll)2e18 + 7LL;
const ld PI = acos(-1);
const int MAX = 5e5+5;
const int dx[] = {1, -1, 0, 0, -1, 1, 1, -1};
const int dy[] = {0, 0, 1, -1, -1, -1, 1, 1};
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
ll Rand(ll l, ll r)
{
return uniform_int_distribution<ll>(l, r)(rd);
}
template<class SHIBA, class ENGINE>
bool minimize(SHIBA &x, const ENGINE y)
{
if(x > y)
{
x = y;
return true;
}
else return false;
}
template<class SHIBA, class ENGINE>
bool maximize(SHIBA &x, const ENGINE y)
{
if(x < y)
{
x = y;
return true;
}
else return false;
}
/* Template by: Nguyen Nhat Anh from Luong Van Chanh High School for the gifted */
/* From Min Tuoi with love */
/** TRY HARD **/
/** ORZ **/
/* -----------------[ MAIN CODE ]----------------- */
#ifdef SHABI
#define press check
string s = "YABXBBABBBAAAXAAABBBBBBABAABABAXABBAAXAABBAAX";
int check(string tmp)
{
FOD(len, (int)min(tmp.size(), s.size()), 1)
{
REP(j, tmp.size() - len + 1) if (tmp.substr(j, len) == s.substr(0, len)) return len;
}
return 0;
}
#endif
string guess_sequence(int n)
{
string res;
vector<string> add;
if (press("AB") >= 1)
{
if (press("A") == 1) res += "A";
else res += "B";
}
else
{
if (press("X") == 1) res += "X";
else res += "Y";
}
if (n == 1) return res;
if (res[0] != 'A') add.pb("A");
if (res[0] != 'B') add.pb("B");
if (res[0] != 'X') add.pb("X");
if (res[0] != 'Y') add.pb("Y");
assert(add.size() == 3);
FOR(i, 2, n-1)
{
string tmp = res + add[0] + res + add[1] + add[2] + res + add[1] + add[0] + res + add[1] + add[1];
int t = press(tmp);
if (t == res.size()) res += add[2];
else
{
if (res.size() + 2 <= t) res += add[1];
else res += add[0];
}
}
if (press(res + add[0]) == n) res += add[0];
else if (press(res + add[1]) == n) res += add[1];
else res += add[2];
return res;
}
#ifdef SHABI
__Shibae__
{
IOS
cout << guess_sequence(s.size());
return 0;
}
#endif
