#include <bits/stdc++.h>
#include "combo.h"
using namespace std;
using ll = long long;
// #define int ll
using P = pair<int, int>;
#define all(x) x.begin(), x.end()
#define rep(i, l, n) for (int i = l; i < (n); ++i)
#define sz(x) (int)x.size()
const char nl = '\n';
string guess_sequence(int n) {
string p;
int x = press("AB");
if (x == 1) {
if (press("A"))p += 'A';
else p += 'B';
} else {
if (press("X"))p += 'X';
else p += 'Y';
}
if (n == 1)return p;
char a, b, c;
if (p[0] == 'A')a = 'B', b = 'X', c = 'Y';
else if (p[0] == 'B')a = 'A', b = 'X', c = 'Y';
else if (p[0] == 'X')a = 'A', b = 'B', c = 'Y';
else a = 'A', b = 'B', c = 'X';
rep(i, 2, n) {
x = press(p+a+p+b+a+p+b+c+p+b+b);
if (x == i)p += a;
else if (x == i+1)p += b;
else p += c;
}
x = press(p+a+p+b);
if (x == n) {
if (press(p+a) == n)return p+a;
else return p+b;
} else return p+c;
}
