You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[(1R)-1-[4-[(5-chlorothiophen-2-yl)methyl]piperazin-1-yl]ethyl]-5-(4-fluorophenyl)-1,3,4-oxadiazole The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H20ClFN4OS
assistant