#include <bits/stdc++.h>
using namespace std;
template <typename T> using ve = vector<T>;
template <typename T, int sz> using ar = array<T, sz>;
typedef long long ll;
#define pb push_back
#define fi first
#define se second
#define endl '\n'
int press(string p);
string guess_sequence(int N) {
// SUbtask N = 3
for(char i : "ABXY") {
for(char j : "ABXY") {
for(char k : "ABXY") {
string limit = "";
limit += i;
limit += j;
limit += k;
if(press(limit)==3){
return limit;
}
}
}
}
return "Hello world";
};
