You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
ethyl (5S)-8-(4-chlorophenyl)-4-(4-methylphenyl)-10-phenyl-1-thia-3,4,9,10-tetrazaspiro[4.5]deca-2,8-diene-2-carboxylate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C27H25ClN4O2S
assistant