CC(C)(C)OC(=O)N1CCC[C@H]1C(=O)N[C@@H](CO)[C@H](O)[C@@H]1C[C@@H]1C(=O)N1CCCC1
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?