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 4-[3-(4-bromophenyl)-5-methyl-1,2-oxazole-4-carbonyl]-N-(oxan-4-yl)-1H-pyrrole-2-carboxamide into molecular formula.
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C21H20BrN3O4
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