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What is the molecular formula of the molecule (1R,9S,12R)-9-methyl-11-oxo-10-[2-(4-sulfamoylphenyl)ethyl]-8-oxa-10-azatricyclo[7.3.1.02,7]trideca-2,4,6-triene-12-carboxylic acid ?
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C21H22N2O6S
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