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 3-[2-[(Z)-[2-(4-bromophenyl)imino-4-oxo-1,3-thiazolidin-5-ylidene]methyl]pyrrol-1-yl]benzoic acid ?
user
C21H14BrN3O3S
assistant