You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[4-oxo-5-[(2-prop-2-enoxyphenyl)methylidene]-2-sulfanylidene-1,3-thiazolidin-3-yl]propanoic acid is the IUPAC name of a molecule. Please give its molecular formula.
user
C16H15NO4S2
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