You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-methyl-2-[[5-methyl-4-(4-methylphenyl)-1,2,4-triazol-3-yl]sulfanyl]-N-phenylacetamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H20N4OS
assistant