You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule 2-[5-[[1-[(2-chloro-6-fluorophenyl)methyl]indol-3-yl]methylidene]-4-oxo-2-sulfanylidene-1,3-thiazolidin-3-yl]acetate .
user
C21H13ClFN2O3S2-
assistant