You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
methyl 2-[[2-[2-[(2-ethoxyphenyl)methylidene]hydrazinyl]-2-oxoacetyl]amino]-5,6-dihydro-4H-cyclopenta[b]thiophene-3-carboxylate is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H21N3O5S
assistant