You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N',N'-dimethyl-N-(9-methyl-3-thiophen-2-yl-[1,2,4]triazolo[4,3-c]quinazolin-5-yl)ethane-1,2-diamine is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H20N6S
assistant