C#CCN(C[C@@H]1[C@@H](OC(=O)NCc2ccccc2)[C@@H](OC(=O)NCc2ccccc2)CN(C(=O)OC(C)C)N1C(=O)OC(C)C)S(=O)(=O)c1ccc(C)cc1
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?