COc1ccc2c(c1)C(=O)N1[C@H]3c4cc(Br)ccc4OC[C@@H]3[C@H](c3ccccc3)[C@]1(C)C(=O)N2
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?