#define F first
#define S second
#define rep(i,a,b) for(int i=a;!(a==b&&i!=b)&&((i<=b&&b>=a)||(i>=b&&a>=b));i+=(a<=b?1:-1))
#define pb push_back
#define Fbitl __builtin_ffs
#define bit1 __builtin_popcount
//#include <bits/stdc++.h>
#include <iostream>
#include <math.h>
#include <algorithm>
#include <string.h>
#include <vector>
#include <queue>
#include <map>
#include <unordered_map>
#include "combo.h"
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<string, string> pss;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<pii> vii;
typedef vector<ll> vl;
typedef vector<vl> vvl;
//press(string);
string sw = " ABXY" ;
int fidx ;
string guess_sequence(int N) {
if ( press("ABA") ) {
if ( press("B") ) fidx = 2 ;
else fidx = 1 ;
}
else {
if ( press("X") ) fidx = 3 ;
else fidx = 4 ;
}
string res = { sw[fidx] } , t ;
if ( N == 1 ) return res ;
for (int j = 1;j<N;j++) {
t += ' ';
for ( int i = 1 ; i <= 4 ; i++ ) {
if ( i == fidx ) continue;
if ( i == 4 || (i == 3&&fidx==4)) {
res += sw[i];
break;
}
t[j] = sw[i];
if ( press(t) == j+1 ) {
res += sw[i];
break;
}
}
}
return res;
}
