You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[1-[1-(3,4-dimethoxyphenyl)sulfonyl-6-fluoroindol-3-yl]ethylideneamino]guanidine The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H20FN5O4S
assistant