CCOC(=O)CCC(C(=O)OCC)n1nnc2ccc(Nc3c(C)[n+]([O-])c4cc(F)c(OCC)cc4[n+]3[O-])cc21
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?