You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3E)-3-[[(1R,2R,4aS,8aR)-2-methyl-1,2,4a,5,6,7,8,8a-octahydronaphthalen-1-yl]-hydroxymethylidene]-5-(1-hydroxyethyl)-1-methylpyrrolidine-2,4-dione is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H27NO4
assistant