You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule 1-[2-(6,7,8,9-tetrahydro-5H-[1,2,4]triazolo[4,3-a]azepin-3-yl)ethyl]-3-([1,2,4]triazolo[1,5-a]pyridin-2-yl)urea into molecular formula.
user
C16H20N8O
assistant