CN(C(=O)COC(=O)c1c2c(nc3ccccc13)/C(=C/c1cccc([N+](=O)[O-])c1)CCC2)C1CCS(=O)(=O)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?