You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance (3S,7aS)-N-[(1S)-1-[4-(difluoromethoxy)phenyl]ethyl]-7a-methyl-5-oxo-2,3,6,7-tetrahydropyrrolo[2,1-b][1,3]thiazole-3-carboxamide .
user
C17H20F2N2O3S
assistant