You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule N-(3-fluorophenyl)-4-[(5E)-5-[(4-methylphenyl)methylidene]-4-oxo-2-sulfanylidene-1,3-thiazolidin-3-yl]butanamide ?
user
C21H19FN2O2S2
assistant