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 [5-chloro-1-(4-fluorophenyl)-3-methylpyrazol-4-yl]-[4-(4-chlorophenyl)sulfonylpiperazin-1-yl]methanone ?
user
C21H19Cl2FN4O3S
assistant