C#CCCOC(=O)N1C2=NC(C(=O)OC)=C(C(=O)OC)[C@@H]3N(C)c4ccc(OC)cc4[C@]23C[C@H]1C(=O)OC
The electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?