COC(=O)[C@@H]1C2CC3c4[nH]c5cc(OC)ccc5c4CCN3CC2C[C@H](OC(=O)c2cc(OC)c(OC)c(OC)c2)C1OC
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?