#include "combo.h"
#include <bits/stdc++.h>
#define pb push_back
#define pf push_front
using namespace std;
#define F first
#define S second
typedef long long ll;
#define pii pair <int, int>
#define pll pair <ll, ll>
typedef long double ld;
const ll N = 2 * 1e5 + 10, len = 316;
const ll mod = 1e9 + 7;
ll um(ll a, ll b){
return ((1LL * a * b) % mod + mod) % mod;
}
ll subr(ll a, ll b){
return ((1LL * a - b) % mod + mod) % mod;
}
string guess_sequence(int n){
string ans = "";
string s = "ABXY";
int fir = -1;
for(int i = 0; i < n; i++){
for(int j = 0; j < 4; j++){
if(fir == j) continue;
int res = press(ans + s[j]);
if(res == i + 1){
if(i == 0) fir = j;
ans += s[j];
break;
}
}
}
return ans;
}
