#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef double ld;
typedef complex<ld> point;
void debug_out(){cerr << endl;}
template<typename Head, typename... Tail>
void debug_out(Head H, Tail... T){
cerr << H << ' ';
debug_out(T...);
}
#define debug(...) cerr << "(" << #__VA_ARGS__ << "): ", debug_out(__VA_ARGS__)
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define MP(x, y) make_pair(x, y)
const int maxn = 2e3 + 10;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int n, ptr[maxn];
vector<string> val[maxn];
std::string guess_sequence(int N) {
n = N;
vector<string> av = {"A", "B", "X", "Y"};
string res;
for (int i = 0; i < 3; i++){
int tmp = press(av[i]);
if (tmp == 1){
res = av[i];
av.erase(av.begin()+i);
}
}
if (res.empty()){
res = av[3];
av.pop_back();
}
for (int i = 1; i < n-1; i++){
string ask = res;
ask += av[0];
ask += res;
ask += av[1];
ask += av[0];
ask += res;
ask += av[1];
ask += av[1];
ask += res;
ask += av[1];
ask += av[2];
int tmp = press(ask);
if (tmp == i){
res += av[2];
}
else if (tmp == i+1){
res += av[0];
}
else{
res += av[1];
}
}
for (int i = 0; i < n; i++){
string ask = res + av[i];
if (press(ask) == n){
res += av[i];
break;
}
}
return res;
}
