#include "combo.h"
#include <bits/stdc++.h>
#define F first
#define S second
#define pb push_back
#define all(x) x.begin(), x.end();
using namespace std;
typedef pair<int, int> pii;
typedef string str;
char c[4] = {'A', 'B', 'X', 'Y'};
string guess_sequence(int n){
str p = "";
p += c[0];
p += c[1];
int res, id;
res = press(p);
if(res == 0){
p = "";
p += c[2];
res = press(p);
if(res) id = 2;
else id = 3;
} else {
p = "";
p += c[0];
res = press(p);
if(res) id = 0;
else id = 1;
}
if(id) swap(c[id], c[0]);
str com = ""; com += c[0];
for(int i = 1; i + 1 < n; i++){
p = "";
p += com; p += c[1];
p += com; p += c[2]; p += c[1];
p += com; p += c[2]; p += c[2];
p += com; p += c[2]; p += c[3];
res = press(p);
if(res == i) com += c[3];
else if(res == i + 1) com += c[1];
else if(res == i + 2) com += c[2];
else assert(0);
}
p = com; p += c[1];
p += com; p += c[2];
if(press(p) == n){
p = com;
p += c[1];
if(press(p) == n) com += c[1];
else com += c[2];
} else {
com += c[3];
}
//cerr << "! " << com << '\n';
return com;
}
