You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[4-[(2-chloro-6-fluorophenyl)methyl]piperazin-1-yl]-2-[[5-(1H-pyrrol-2-yl)-1,3,4-oxadiazol-2-yl]sulfanyl]ethanone is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H19ClFN5O2S
assistant