You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Convert the IUPAC name of a molecule (2R,3R,4S,5R)-2-[2-cyclohexylsulfanyl-6-(ethylamino)purin-9-yl]-5-(hydroxymethyl)oxolane-3,4-diol into molecular formula.
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C18H27N5O4S
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