#include "combo.h"
#pragma GCC optimize ("Ofast")
#include <bits/stdc++.h>
using namespace std;
#define pb push_back
set<pair<int, char>> vis;
string guess_sequence(int N) {
string p;
for (char i : {'A', 'B', 'X', 'Y'}) {
p.pb(i);
if (press(p)) {
for (int i = 1; i < N; i++) {
p.pb(i);
}
break;
}
p.pop_back();
}
vector<char> v;
for (char i : {'A', 'B', 'X', 'Y'}) {
if (p[0] == i) continue;
v.pb(i);
}
int idx = 1;
while (idx < N) {
for (int j = 0; j < 3; j++) {
int k = j + rand() % (3 - j);
swap(v[j], v[k]);
}
for (int i = idx+1; i - idx + 1 <= idx && i < N; i++) {
while (p[i] == p[0] || vis.count(make_pair(i, p[i]))) {
p[i] = v[rand() % 3];
}
}
idx = press(p);
}
return p;
}
