You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[2-[3-[2-(2-ethoxyanilino)-2-oxoethyl]sulfanylindol-1-yl]ethyl]-4-nitrobenzamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C27H26N4O5S
assistant