You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2S)-3-(3-chloro-4-methylphenyl)-1'-[[4-(2-fluorophenyl)piperazin-1-yl]methyl]spiro[1,3-thiazolidine-2,3'-indole]-2',4-dione The above is the IUPAC name of a molecule. Write its molecular formula.
user
C28H26ClFN4O2S
assistant