You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Translate the chemical IUPAC name 1-(3-chlorophenyl)-3-[[2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindol-4-yl]methyl]urea into its molecular formula.
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C21H17ClN4O5
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