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 ethyl 5-[[2-[1-(4-fluorophenyl)pyrazolo[3,4-d]pyrimidin-4-yl]sulfanylacetyl]amino]-3-methylthiophene-2-carboxylate into molecular formula.
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C21H18FN5O3S2
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