CC[N+]1(C)[C@H]2CC[C@@H]1CC(OC(=O)[C@H]1CC[C@@](C(=O)OC3C[C@@H]4CC[C@H](C3)[N+]4(C)CC)(c3ccccc3)c3ccccc31)C2
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?