CC(C)C(C(=O)N1CCC[C@@H]1C(=O)OCc1ccccc1)N(C)C(=O)C(C(C)C)N(C)C(=O)[C@H](Cc1ccccc1)N(C)C(=O)[C@H](NC(=O)OC(C)(C)C)C(C)C
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?