O=C(C=P(c1ccccc1)(c1ccccc1)c1ccccc1)c1ccccc1-c1ccccc1C(=O)C=P(c1ccccc1)(c1ccccc1)c1ccccc1
Molecules possible for drug usually have no more than 5 Hydrogen bond acceptor. How many hydrogen bond acceptors does the molecule have?