#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 check, s = "ABXY";
int fir, n1, n2, n3;
void create(int cur, int sz, string next){
if(cur == sz){
check += next;
return;
}
create(cur + 1, sz, next + s[n1]);
create(cur + 1, sz, next + s[n2]);
}
string guess_sequence(int n){
n1 = n2 = n3 = -1;
if(press("AB") >= 1){
if(press("A") == 1) fir = 0;
else fir = 1;
} else{
if(press("X") == 1) fir = 2;
else fir = 3;
}
string ans = "";
ans += s[fir];
int cur = 1;
for(int i = 0; i < 4; i++){
if(i == fir) continue;
if(n1 == -1) n1 = i;
else{
if(n2 == -1) n2 = i;
else n3 = i;
}
}
while(cur < n){
int sz = cur, cnt = 1;
while(true){
if((sz + 1) * cnt * 2 > 4 * n || sz + 1 > n){
check = "";
create(cur, sz, ans);
int res = press(check);
while(cur < res){
if(press(ans + s[n1]) == cur + 1){
ans += s[n1];
} else ans += s[n2];
cur++;
}
if(res < sz){
ans += s[n3];
cur++;
}
break;
}
sz++;
cnt *= 2;
}
}
return ans;
}
