You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[(4-benzyl-5-pyridin-3-yl-1,2,4-triazol-3-yl)sulfanyl]-N-(3-methylbutyl)acetamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H25N5OS
assistant