You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2Z)-5-[(2,5-dichlorophenyl)methyl]-2-[(E)-naphthalen-1-ylmethylidenehydrazinylidene]-1,3-thiazolidin-4-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H15Cl2N3OS
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