You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the compound with this IUPAC name (7S,8aS)-7-(3-fluorophenoxy)-2-[(5-methylthiophen-2-yl)methyl]-3,4,6,7,8,8a-hexahydro-1H-pyrrolo[1,2-a]pyrazine ?
user
C19H23FN2OS
assistant