You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Name the molecular formula for the molecule established as 1-(3-methylphenyl)-3-[3-methylsulfanyl-1-([1,2,4]triazolo[4,3-a]pyridin-3-yl)propyl]urea using the IUPAC nomenclature.
user
C18H21N5OS
assistant