COc1ccc([C@H]2[C@H](C(=O)OC(C)(C)C)N3N=Cc4ccccc4C3C23C(=O)c2ccccc2C3=O)cc1OC
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?