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What is the molecular formula of the compound with this IUPAC name (1S,6S,9R,10S,15S,18R)-8-(6-amino-4,5-dihydropurin-9-yl)-17-(6-aminopurin-9-yl)-3-hydroxy-12-oxo-12-sulfanyl-3-sulfanylidene-4,7,13,16-tetraoxa-2,11-diaza-3lambda5,12lambda5-diphosphatricyclo[13.3.0.06,10]octadecane-9,18-diol ?
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C20H28N12O8P2S2
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