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 2-[[4-[(1,3-dioxoisoindol-2-yl)methyl]-1,3,5-triazin-2-yl]methyl]isoindole-1,3-dione into molecular formula.
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C21H13N5O4
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