O=C1[C@H]2[C@@H](C(=O)N1c1ccccc1)[C@@H](/C=C/c1ccccc1)N1C(=O)CN(Cc3ccccn3)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?