You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the molecule 2-[5-[(4-hydroxy-3,5-dimethoxyphenyl)methylidene]-4-oxo-2-sulfanylidene-1,3-thiazolidin-3-yl]propanoic acid ?
user
C15H15NO6S2
assistant