#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define sp <<" "<<
#define endl "\n"
#define all(x) (x).begin(), (x).end()
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
string guess_sequence(int N) {
string p = "";
vector<char> st = {'A', 'B', 'X', 'Y'};
shuffle(all(st), rng);
// find first character in 2 queries
{
p = st[0] + st[1];
int x = press(p);
if (x >= 1) {
p = st[0];
x = press(p);
p = (x == 1 ? st[0] : st[1]);
} else {
p = st[2];
x = press(p);
p = (x == 1 ? st[2] : st[3]);
}
st.erase(find(all(st), p[0]));
}
// find the rest of the characters
{
int t = 2;
for (; t <= N; t++) {
shuffle(all(st), rng);
string q = "";
q += p + st[1];
q += p + st[2] + st[0];
q += p + st[2] + st[1];
q += p + st[2] + st[2];
if (q.size() > 4 * N) break;
int x = press(q);
if (x == t-1) {
p += st[0];
} else if (x == t) {
p += st[1];
} else if (x == t+1) {
p += st[2];
} else assert(0);
}
// t == N
for (; t <= N; t++) {
shuffle(all(st), rng);
string q;
for (int i = 0; i < 2; i++) {
q = (p + st[i]);
// cerr << q << endl;
int x = press(q);
if (x == t) {
p = q;
break;
}
}
if (p.size() != t) {
p += st[2];
}
}
}
// cerr << p << endl;
return p;
}
