You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-(2-fluorophenyl)-4-[(E)-(2,3,4-trimethoxyphenyl)methylideneamino]-1H-1,2,4-triazole-5-thione is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H17FN4O3S
assistant