You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 2-[2-[2-(5-ethyl-4-methylthiophene-2-carbonyl)hydrazinyl]-2-oxoethyl]sulfanyl-N-(4-fluorophenyl)acetamide into its molecular formula.
user
C18H20FN3O3S2
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