#include <bits/stdc++.h> using namespace std; #define ll long long const ll mmod = 998244353; #define vl vector<long long> #define vll vector<vector<long long>> #define pl pair<long long, long long> #define vb vector<bool> #include "combo.h" string guess_sequence(int N){ string z = "ABXY"; ll i = 3; ll c = press("AB"); if (c >= 1){ if (press("B") == 1){ i = 1; } else{ i = 0; } } else{ if (press("X") == 1){ i = 2; } } swap(z[i], z[0]); string s(1, z[0]); for (ll i = 1; i < N-1; i++){ string ns = s; string ans = ns + z[1] + ns + z[2] + z[1] + ns + z[2] + z[2] + ns + z[2] + z[3]; ll c = press(ans); if (c == s.size()){ s += z[3]; } else if (c == s.size()+1){ s += z[1]; } else{ s += z[2]; } } if (N > 1){ if (press(s + z[1] + s + z[2]) == N){ if (press(s + z[1]) == N){ s += z[1]; } else{ s += z[2]; } } else{ s+=z[3]; } } return s; }