COC(=O)[C@H]1C[C@H](OC(=O)NC2CC2)[C@@]2(O)CN(S(=O)(=O)c3ccc(C)cc3)CC2[C@H]1C(=O)OC
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?