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-[2-oxo-3-[(5S)-2-oxo-5-propan-2-yl-3-[6-(trifluoromethyl)pyridin-3-yl]imidazolidin-1-yl]propyl]pyridine-3-carbonitrile by IUPAC nomenclature, provide its molecular formula.
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C21H20F3N5O2
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