COC(=O)[C@H](Cc1ccccc1)NC(=O)O[C@@H]1C(=O)c2cc(OC)ccc2O[C@H]1c1ccc(OC)c(Br)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?