O=C(/C=C(\S/C=C(/c1ccccc1)N1CCn2c(C(=O)c3ccccc3)c(C(=O)c3ccccc3)c(C(=O)c3ccccc3)c21)C(=O)c1ccccc1)c1ccccc1
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?