#ifdef AIMAN
#define _GLIBCXX_DEBUG
#endif
#include "combo.h"
#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define pb push_back
#define eb emplace_back
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("fast-math")
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimize("O2")
using ll = long long;
ll inf = 1e9;
using namespace std;
string guess_sequence(int n) {
string ans;
int matched = 0;
int x = press("AB");
if (x == 0) {
x = press("X");
ans += (x == 1 ? 'X' : 'Y');
} else {
x = press("A");
ans += (x == 1 ? 'A' : 'B');
}
matched = 1;
while (matched + 2 <= n) {
char s0 = ans[0];
if (s0 == 'A') {
x = press(ans + "BB" + ans + "BX" + ans + "BY" + ans + "X");
ans += (x == matched ? 'Y'
: (x == matched+1 ? 'X' : 'B'));
}
else if (s0 == 'B') {
x = press(ans + "AA" + ans + "AX" + ans + "AY" + ans + "X");
ans += (x == matched ? 'Y'
: (x == matched+1 ? 'X' : 'A'));
}
else if (s0 == 'X') {
x = press(ans + "AA" + ans + "AB" + ans + "AY" + ans + "B");
ans += (x == matched ? 'Y'
: (x == matched+1 ? 'B' : 'A'));
}
else {
x = press(ans + "BB" + ans + "BX" + ans + "BA" + ans + "X");
ans += (x == matched ? 'A'
: (x == matched+1 ? 'X' : 'B'));
}
matched++;
}
if (matched == n-1) {
char s0 = ans[0];
if (s0 == 'A') {
x = press(ans + "B");
if (x == n) ans += 'B';
else {
x = press(ans + "X");
ans += (x == n ? 'X' : 'Y');
}
}
else if (s0 == 'B') {
x = press(ans + "A");
if (x == n) ans += 'A';
else {
x = press(ans + "X");
ans += (x == n ? 'X' : 'Y');
}
}
else if (s0 == 'X') {
x = press(ans + "A");
if (x == n) ans += 'A';
else {
x = press(ans + "B");
ans += (x == n ? 'B' : 'Y');
}
}
else {
x = press(ans + "B");
if (x == n) ans += 'B';
else {
x = press(ans + "X");
ans += (x == n ? 'X' : 'A');
}
}
}
return ans;
}
