C#C[C@]1(O)CC[C@H]2[C@@H]3CCC4=C/C(=N/CCOC(=O)c5cccc6cc7ccccc7nc56)CC[C@@H]4[C@H]3CC[C@@]21C
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?