You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3aS,4S,7aR)-4-ethyl-2-[[3-(furan-2-yl)-1,2,4-oxadiazol-5-yl]methyl]-3,3a,5,6,7,7a-hexahydro-1H-isoindol-4-ol is the IUPAC name of a molecule. Please give its molecular formula.
user
C17H23N3O3
assistant