#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; #define REP(i, n) for (int (i) = 0; (i) < (n); (i)++) #define FOR(i, a, b) for (int (i) = (a); (i) < (b); (i)++) #define RREP(i, a) for(int (i) = (a) - 1; (i) >= 0; (i)--) #define FORR(i, a, b) for(int (i) = (a) - 1; (i) >= (b); (i)--) #define DEBUG(C) cerr << #C << " = " << C << endl; using LL = long long; using VI = vector; using VVI = vector; using VL = vector; using VVL = vector; using VD = vector; using VVD = vector; using PII = pair; using PDD = pair; using PLL = pair; using VPII = vector; template using VT = vector; #define ALL(a) begin((a)), end((a)) #define RALL(a) rbegin((a)), rend((a)) #define SORT(a) sort(ALL((a))) #define RSORT(a) sort(RALL((a))) #define REVERSE(a) reverse(ALL((a))) #define MP make_pair #define FORE(a, b) for (auto &&a : (b)) #define FIND(s, e) ((s).find(e) != (s).end()) #define EB emplace_back const int INF = 1e9; const int MOD = INF + 7; const LL LLINF = 1e18; int N; int grandy[110]; int calcGrandy(int n) { int &now = grandy[n]; if (now != -1) return now; if (n == 0) return now = 0; set se; if (n >= 2) { se.insert(calcGrandy(n / 2)); if (n % 2) se.insert(calcGrandy((n / 2) + 1)); } if (n >= 3) { se.insert(calcGrandy(n / 3)); if (n % 3) se.insert(calcGrandy((n / 3) + 1)); } now = 0; while (FIND(se, now)) now++; return now; } int main(void) { REP(i, 110) grandy[i] = -1; cin >> N; if (N == 1 || N == 3) { cout << "B" << endl; return 0; } if (N == 2) { cout << "A" << endl; return 0; } calcGrandy(N); bool ok = false; if (N % 2 == 0) { ok |= ((grandy[N / 2] ^ grandy[N / 2]) == 0); } else { ok |= ((grandy[N / 2] ^ grandy[(N / 2) + 1]) == 0); } if (N % 3 == 0) { ok |= ((grandy[N / 3] ^ grandy[N / 3] ^ grandy[N / 3]) == 0); } else if (N % 3 == 1) { ok |= ((grandy[(N / 3) + 1] ^ grandy[N / 3] ^ grandy[N / 3]) == 0); } else { ok |= ((grandy[(N / 3) + 1] ^ grandy[(N / 3) + 1] ^ grandy[N / 3]) == 0); } cout << (ok ? "A" : "B") << endl; }