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-[[5-[1-(4-fluorophenoxy)ethyl]-1,3,4-oxadiazol-2-yl]sulfanyl]-1-[5-(pyrrolidine-1-carbonyl)-1H-pyrrol-3-yl]ethanone into molecular formula.
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C21H21FN4O4S
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