Cc1cccc(-c2ccc3[nH]c4c(c3c2)CCN2C[C@@H]([C@H](C)O)[C@@H](N(C)C(=O)NC3CCCCC3)C[C@@H]42)c1
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?