You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 1-[3-[(3,4-dichlorophenyl)methoxy]-2-[(2,4-dichlorophenyl)methylsulfanyl]propyl]imidazole by IUPAC nomenclature, provide its molecular formula.
user
C20H18Cl4N2OS
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