You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(1S,8aS)-7-(2-hydroxyethyl)-N-methyl-1-(2-methylphenyl)-N-[(1S)-1-[3-methyl-5-(trifluoromethyl)phenyl]ethyl]-6-oxo-7-(3-oxopropyl)-3,4,8,8a-tetrahydro-1H-pyrrolo[1,2-a]pyrazine-2-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C31H38F3N3O4
assistant