#include "combo.h"
#include <bits/stdc++.h>
#define pb push_back
#define ppb pop_back
#define fi first
#define se second
#define mid ((x + y) / 2)
#define left (ind * 2)
#define right (ind * 2 + 1)
#define mp make_pair
#define timer ((double)clock() / CLOCKS_PER_SEC)
#define endl "\n"
#define spc " "
#define d1(x) cerr<<#x<<":"<<x<<endl
#define d2(x, y) cerr<<#x<<":"<<x<<" "<<#y<<":"<<y<<endl
#define d3(x, y, z) cerr<<#x<<":"<<x<<" "<<#y<<":"<<y<<" "<<#z<<":"<<z<<endl
#define fast_io() ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0)
using namespace std;
typedef long long int lli;
typedef pair<int, int> ii;
typedef pair<ii, int> iii;
typedef pair<double, double> dd;
const int N = (int)(1e6 + 5);
const int LOG = (int)(20);
string s;
set<char> ost;
vector<char> oth;
std::string guess_sequence(int N) {
ost.insert('A');
ost.insert('B');
ost.insert('X');
ost.insert('Y');
if(press("AB") != 0) {
if(press("A") != 0) {
s.pb('A');
ost.erase('A');
}
else {
s.pb('B');
ost.erase('B');
}
}
else {
if(press("X") != 0) {
s.pb('X');
ost.erase('X');
}
else {
s.pb('Y');
ost.erase('Y');
}
}
for(auto i : ost)
oth.pb(i);
for(int i = 1; i < N - 1; i++) {
string ask = s + oth[0] + s + oth[1] + oth[0] + s + oth[1] + oth[1] + s + oth[1] + oth[2];
int re = press(ask);
if(re == (int)s.size())
s.pb(oth[2]);
if(re == (int)s.size() + 1)
s.pb(oth[0]);
if(re == (int)s.size() + 2)
s.pb(oth[1]);
}
if(N != 1) {
if(press(s + oth[0] + s + oth[1]) == (int)s.size() + 1) {
if(press(s + oth[0]) == (int)s.size() + 1)
return s + oth[0];
else
return s + oth[1];
}
else
return s + oth[2];
}
return s;
}
