You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(8S)-8-(4-morpholin-4-ylphenyl)-7,8-dihydro-5H-[1,3]dioxolo[4,5-g]quinolin-6-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H20N2O4
assistant