You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule 1-[4-[(3-fluoro-4-methoxyphenyl)methyl]piperazin-1-yl]-2-[(5-thiophen-2-yl-1,3,4-oxadiazol-2-yl)sulfanyl]ethanone into molecular formula.
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C20H21FN4O3S2
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