O=C(NCC(F)([N+](=O)[O-])[N+](=O)[O-])N(CC(F)([N+](=O)[O-])[N+](=O)[O-])CC(F)([N+](=O)[O-])[N+](=O)[O-]
Molecules possible for drug usually have no more than 5 Hydrogen bond acceptor. How many hydrogen bond acceptors does the molecule have?