O=C(CC[N+](=O)[O-])OCC1OC(O)C(OC(=O)CC[N+](=O)[O-])[C@@H](OC(=O)CC[N+](=O)[O-])C1OC(=O)CC[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?