CCOC(=O)c1c(-c2cccc3ccccc23)c(C#N)c(=S)n(C2OC(COC(C)=O)C(OC(C)=O)C(OC(C)=O)C2OC(C)=O)c1C
The electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?