You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 2,4-difluoro-N-[2-[2-[2-nitro-4-(trifluoromethyl)anilino]ethylamino]-2-oxoethyl]benzamide by IUPAC nomenclature, provide its molecular formula.
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C18H15F5N4O4
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