You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the molecule [(5S,7aS)-2-[4-cyano-3-(trifluoromethyl)phenyl]-4,7-dimethyl-1,3-dioxo-3a,5,6,7a-tetrahydro-4,7-epoxyisoindol-5-yl] acetate ?
user
C20H17F3N2O5
assistant