You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 2-[(8-ethyl-2-phenyl-1,4,8-triazaspiro[4.5]deca-1,3-dien-3-yl)sulfanyl]-N-(2-fluorophenyl)acetamide into its molecular formula.
user
C23H25FN4OS
assistant