You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 3-(2-amino-5-chloropyridin-4-yl)-6-[(3S,4S)-4-amino-3-methyl-2-oxa-8-azaspiro[4.5]decan-8-yl]-5-methyl-2H-pyrazolo[3,4-d]pyrimidin-4-one by IUPAC nomenclature, provide its molecular formula.
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C20H25ClN8O2
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