You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
methyl 3-[2-[(4R,5R)-3-(4-chlorophenyl)-5-pyridin-2-yl-2-sulfanylideneimidazolidin-4-yl]pyrrol-1-yl]benzoate is the IUPAC name of a molecule. Please give its molecular formula.
user
C26H21ClN4O2S
assistant