C[C@@H]1NC(=O)C/C=C\[C@@H](C)[C@@H]2C=C[C@H](O)[C@@H](COC(=O)[C@H](C)NC(=O)C/C=C\[C@@H](C)[C@@H]3C=C[C@H](O)[C@@H](COC1=O)O3)O2
The electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?