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-[(2,5-dioxopyrrolidin-1-yl)methyl]-N-methyl-N-[1-(3-nitrophenyl)ethyl]benzamide is given. What is its corresponding molecular formula?
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C21H21N3O5
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