COc1ccc(C2CC(=O)c3cc(-c4nc(-c5cccc([N+](=O)[O-])c5)cs4)c(=O)n(-c4cccc(C)c4)c3C2)cc1
Hydrogen bond acceptor is the chemical compound which contains the lone electron pairs that participate in the hydrogen bond formation. How many hydrogen bond acceptors does the molecule contain?