COCCn1c(C(=O)N2CCCC2)cc2c1C[C@H]1CN(C(=O)c3ccccc3)[C@@](Cc3ccccc3)(C(=O)OC)[C@@H]21
The electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?