COc1cccc(-c2[nH]c3c(c2-c2c(-n4cccc4)n(C)c(=O)[nH]c2=O)c(=O)[nH]c(=O)n3C)c1
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?