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 N-cyclohexyl-2-[[7-(3,4-dimethylphenyl)-8-oxo-[1,2,4]triazolo[4,3-a]pyrazin-3-yl]sulfanyl]acetamide ?
user
C21H25N5O2S
assistant