CCC(=O)[C@@]1(C)[C@H](C)C[C@@H]2[C@@H]3CCC4=CC(=O)C=C[C@@]4(C)[C@H]3[C@H](O)C[C@]21C
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?