You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 2-[[5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrophenyl]methyl]-4-trimethylsilylbutanethioic S-acid by IUPAC nomenclature, provide its molecular formula.
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C21H23ClF3NO4SSi
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