#include <bits/stdc++.h>
// mrrrow meeow :3
// go play vivid/stasis now! it's free on steam
#define fo(i, a, b) for (auto i = (a); i < (b); i++)
#define of(i, a, b) for (auto i = (b); i-- > (a);)
#define f first
#define s second
#define pb push_back
#define pob pop_back
#define lb lower_bound
#define ub upper_bound
#define be(a) a.begin(), a.end()
using namespace std;
int ____init = [] {
ios::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
return 0;
}();
int press(string p);
string guess_sequence(int n) {
char cs[4] = {'A', 'B', 'X', 'Y'};
if (press("AB")) {
if (press("A")) {
swap(cs[3], cs[0]);
} else {
swap(cs[3], cs[1]);
}
} else {
if (press("X")) {
swap(cs[3], cs[2]);
} else {
swap(cs[3], cs[3]);
}
}
string res;
res += cs[3];
if (n == 1) return res;
fo(i, 1, n - 1) {
res += cs[press(res + cs[1] + res + cs[2] + cs[0] + res + cs[2] + cs[1] + res + cs[2] + cs[2]) - res.size()];
}
if (press(res + cs[0]) - res.size()) {
res += cs[0];
} else if (press(res + cs[1]) - res.size()) {
res += cs[1];
} else {
res += cs[2];
}
return res;
}
