#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define all(a) (a).begin(), (a).end()
#define replr(i, a, b) for (int i = int(a); i <= int(b); ++i)
#define reprl(i, a, b) for (int i = int(a); i >= int(b); --i)
#define rep(i, n) for (int i = 0; i < int(n); ++i)
#define mkp(a, b) make_pair(a, b)
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> PII;
typedef vector<int> VI;
typedef vector<PII> VPI;
typedef vector<VI> VVI;
typedef vector<VVI> VVVI;
typedef vector<VPI> VVPI;
typedef pair<ll, ll> PLL;
typedef vector<ll> VL;
typedef vector<PLL> VPL;
typedef vector<VL> VVL;
typedef vector<VVL> VVVL;
typedef vector<VPL> VVPL;
template<class T> T setmax(T& a, T b) {if (a < b) return a = b; return a;}
template<class T> T setmin(T& a, T b) {if (a < b) return a; return a = b;}
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template<class T>
using indset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#include "combo.h"
string guess_sequence(int n) {
string s;
if (press("AB")) {
if (press("A")) s.pb('A');
else s.pb('B');
} else {
if (press("X")) s.pb('X');
else s.pb('Y');
}
string ret = s;
if ('A' != s[0]) s.pb('A');
if ('B' != s[0]) s.pb('B');
if ('X' != s[0]) s.pb('X');
if ('Y' != s[0]) s.pb('Y');
rep(i, n-2) {
string qr;
qr += ret;
qr.pb(s[1]);
qr += ret;
qr.pb(s[2]);
qr.pb(s[1]);
qr += ret;
qr.pb(s[2]);
qr.pb(s[2]);
qr += ret;
qr.pb(s[2]);
qr.pb(s[3]);
int cnt = press(qr)-ret.size();
if (cnt == 0) ret.pb(s[3]);
else if (cnt == 1) ret.pb(s[1]);
else if (cnt == 2) ret.pb(s[2]);
/*cout << "CURRENT GUESS: " << ret << endl;*/
}
ret.pb(s[1]);
if (press(ret) == n) return ret;
ret.pop_back();
ret.pb(s[2]);
if (press(ret) == n) return ret;
ret.pop_back();
ret.pb(s[3]);
return ret;
}
