O=C(N[C@@H]1C/C=C\C[C@@H](CC(=O)N(CCO)Cc2ccccc2)C(=O)NCCOC1=O)OCC1c2ccccc2-c2ccccc21
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?