COC(=O)CNC(=O)C(CSC(=O)OCC1c2ccccc2-c2ccccc21)NC(=O)CCC(NC(=O)OCC1c2ccccc2-c2ccccc21)C(=O)OC
The electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?