#include "combo.h"
#include <bits/stdc++.h>
// #define int long long
#define arr2 array<int, 2>
#define arr3 array<int, 3>
#define all(a) a.begin(), a.end()
#define double long double
// #pragma GCC target("avx2")
using namespace std;
string s;
vector<char> chs = {'A', 'B', 'X', 'Y'};
string guess_sequence(int n) {
for (int i = 0; i < n; ++i) {
for (int j = 0; j < chs.size(); ++j) {
if (press(s + chs[j]) > s.size()) {
s += chs[j];
if (j == 0) {
swap(chs[j], chs.back());
chs.pop_back();
}
break;
}
}
}
return s;
}
