You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(E)-3-(2-chlorophenyl)-N-[2-(2,3-dihydroindol-1-ylsulfonyl)ethyl]prop-2-enamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H19ClN2O3S
assistant