You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (4R,5S)-5-[1-(5-chloropyridin-2-yl)pyrrol-2-yl]-4-pyridin-2-yl-1-(pyridin-2-ylmethyl)imidazolidine-2-thione by IUPAC nomenclature, provide its molecular formula.
user
C23H19ClN6S
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