C[C@]12CC[C@H]3[C@@H](CCC4=C[C@@H](N5CCCC5)CC[C@@]43C)[C@@H]1C/C(=C\c1ccncc1)[C@@H]2O
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?