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What is the molecular formula of the molecule identified by ethyl (6R)-10-chloro-9-hydroxy-3,3-dimethyl-15-oxo-1,2-diazatetracyclo[11.4.0.02,6.07,12]heptadeca-7,9,11,13,16-pentaene-16-carboxylate ?
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C20H21ClN2O4
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