You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named 4-chloro-N-[2-(5-ethyl-4-methyl-6-oxo-1H-pyrimidin-2-yl)-5-thiophen-2-ylpyrazol-3-yl]-3-nitrobenzamide is given. What is its corresponding molecular formula?
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C21H17ClN6O4S
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