You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance (5Z,7Z)-2-(3-methyl-3-azabicyclo[3.1.1]heptan-1-yl)-9-methylidene-4H-1,3-thiazonine .
user
C15H20N2S
assistant