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 5-pyridin-4-yl-N-spiro[5,7-dihydro-4H-1,3-benzothiazole-6,4'-oxane]-2-yl-1H-pyrazole-4-carboxamide into molecular formula.
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C20H21N5O2S
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