NCCCCNCCCNC(=O)CNC(=O)CC(O)C(N)CCCC(NC(=O)C(CN)NC(=O)C(O)CNC(=O)CC(N)c1ccc(O)cc1)C(=O)O
The electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?