#include "combo.h"
#include<bits/stdc++.h>
using namespace std;
typedef pair<int, int> ii;
typedef long long ll;
typedef vector<ll> vll;
typedef pair<long long, long long> pll;
typedef pair<char, int> ci;
typedef pair<string, int> si;
typedef long double ld;
typedef vector<int> vi;
typedef vector<string> vs;
#define pb push_back
#define fi first
#define se second
#define whole(v) v.begin(), v.end()
#define rwhole(v) v.rbegin(), v.rend()
#define inf INT_MAX/2
#define fro front
std::string guess_sequence(int N) {
string s;
char fi;
int c = press("A");
if(c){
fi = 'A';
}else{
c = press("B");
if(c){
fi = 'B';
}else{
c = press("X");
if(c){
fi = 'X';
}else{
fi = 'Y';
}
}
}
char x = 'Y';
if(fi == 'Y'){
x = 'X';
}
char y = 'B';
if(fi == 'B'){
y = 'X';
}
char z = 'A';
if(fi == 'A'){
z = 'X';
}
s.pb(fi);
int lc = 1;
for(int i = 1; i < N; ++i){
if(lc > i){
continue;
}
int c;
if(i == N-1){
c = press(s + x);
if(c > lc){
s.pb(x);
}else{
c = press(s + y);
if(c > lc){
s.pb(y);
}else{
s.pb(z);
}
}
break;
}
string a[4];
a[0] = s + x + y;
a[1] = s + y + x;
a[2] = s + x + x;
a[3] = s + y + y;
c = press(a[0] + a[1] + a[2] + a[3]);
if(c == lc){
s.pb(z);
lc++;
}else if(lc + 1 == c){
c = press(a[0]);
if(c > lc){
s.pb(x);
}else{
s.pb(y);
}
s.pb(z);
lc += 2;
}else{
c = press(a[0]);
if(c == lc+1){
s.pb(x);
s.pb(x);
}else if(c == lc){
s.pb(y);
s.pb(x);
}else{
s.pb(x);
s.pb(y);
}
lc += 2;
}
}
//cout << s << endl;
return s;
}
