CC(C)(C)N1C(=O)[C@H]2[C@@H](C1=O)[C@@H](c1ccc(Br)cc1)N1C(=O)N(c3cccc(Cl)c3)C(=O)[C@@]21Cc1ccccc1
The electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?