You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-(6-fluoro-1H-benzimidazol-2-yl)-N-(6-methyl-4,5,6,7-tetrahydro-1,3-benzothiazol-2-yl)propanamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H19FN4OS
assistant