COc1ccc(C#Cc2cnc3c(c2)C(=O)N([C@H](C)CO)C[C@H](C)[C@@H](CN(C)C(=O)Nc2cccc(OC)c2)O3)cc1
Hydrogen bond acceptor is the chemical compound which contains the lone electron pairs that participate in the hydrogen bond formation. How many hydrogen bond acceptors does the molecule contain?