CC(=O)O[C@@H]1[C@@H](O)C2=C3[C@@]4(C)[C@H](CC(=O)C(C)(C)[C@H]14)[C@]3(O)[C@H](OC(C)=O)[C@@]1(C[C@@H]1C)C2=O
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?