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What is the molecular formula of the compound with this IUPAC name [(2S,3S,4R,5R)-2-(5-tert-butyl-1,3,4-oxadiazol-2-yl)-5-[2-chloro-6-(cyclopentylamino)purin-9-yl]-4-hydroxyoxolan-3-yl] formate ?
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C21H26ClN7O5
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