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 2-[ethyl-[1-[5-(4-nitrophenyl)-1,3,4-oxadiazol-2-yl]ethyl]amino]-N-[(4-fluorophenyl)methyl]acetamide into molecular formula.
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C21H22FN5O4
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