You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(5,6-dimethyl-[1,2,4]triazolo[1,5-a]pyrimidin-7-yl)-2-(4-fluorophenyl)-4,5,6,7-tetrahydro-1,3-benzothiazol-4-amine The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H19FN6S
assistant