You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Translate the chemical IUPAC name (3R)-1-[8-chloro-6-[1-(7H-purin-6-ylamino)ethyl]imidazo[1,5-a]pyridin-5-yl]pyrrolidin-3-ol into its molecular formula.
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C18H19ClN8O
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