You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 6-bromo-N-[2-fluoro-5-[5-(3-hydroxy-3-methylbutyl)-1,2,4-oxadiazol-3-yl]phenyl]imidazo[1,2-a]pyridine-3-carboxamide by IUPAC nomenclature, provide its molecular formula.
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C21H19BrFN5O3
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