You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name (4-methylsulfonylpiperazin-1-yl)-[6-methyl-1-(thiophen-2-ylmethyl)pyrazolo[3,4-b]pyridin-4-yl]methanone into its molecular formula.
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C18H21N5O3S2
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