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 2-(1,3-dioxoisoindol-2-yl)-3-methyl-N-[3-(4-methylpiperazin-1-yl)propyl]butanamide is given. What is its corresponding molecular formula?
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C21H30N4O3
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