CCC1=C2CC[C@H]3C(=O)N(CC)C(=O)[C@H]3[C@H]2[C@@]2(C)/C(=N/CCc3c[nH]c4ccccc34)OC(=O)N2C1=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?