CC(=O)NC1(C(=O)N[C@@H](Cc2ccccc2)C(=O)NC2CCCCC2)Cc2ccc3ccccc3c2-c2c(ccc3ccccc23)C1
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?