COCC1=C2c3ccccc3[C@H](C[N+](=O)[O-])C(C(=O)OC)(C(=O)OC)C[C@@H]2n2c(=O)n(-c3ccccc3)c(=O)n2C1
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?