You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name ethyl 2-[[2-(furan-2-ylmethylamino)acetyl]amino]-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxylate into its molecular formula.
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C18H22N2O4S
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