You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-(oxolan-2-ylmethyl)-1-[3-(6,7,8,9-tetrahydro-5H-[1,2,4]triazolo[4,3-a]azepin-3-yl)propyl]guanidine is the IUPAC name of a molecule. Please give its molecular formula.
user
C16H28N6O
assistant