You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(3-methyl-1,2,4-thiadiazol-5-yl)-1,2,3,4,4a,5,6,7,8,8a-decahydroquinoline-2-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C13H20N4OS
assistant