#include "combo.h"
#include <bits/stdc++.h>
#define ios ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define file(s) if (fopen(s".in", "r")) freopen(s".in", "r", stdin), freopen(s".out", "w", stdout)
#define all(a) a.begin() , a.end()
#define F first
#define S second
using namespace std;
using ll = long long;
const ll N = 1e6+5 , inf = 2e9 + 7 , block = 1000;
const ll INF = 1e18 , mod = 1e9+7;
string guess_sequence(int N) {
string s = "";
if(press("A")) s = "A";
else if(press("Y")) s = "Y";
else if(press("X")) s = "X";
else s = "B";
for(int i = 1; i < N; i++){
if('B' != s[0]) {
s += "B";
if(press(s)) continue;
s.pop_back();
}
if('A' != s[0]) {
s += "A";
if(press(s)) continue;
s.pop_back();
}
if('X' != s[0]) {
s += "X";
if(press(s)) continue;
s.pop_back();
}
if('Y' != s[0]) {
s += "Y";
if(press(s)) continue;
s.pop_back();
}
}
return s;
}
