You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(4R,5R)-1-cyclopentyl-4-pyridin-2-yl-5-(1H-pyrrol-2-yl)imidazolidine-2-thione The above is the IUPAC name of a molecule. Write its molecular formula.
user
C17H20N4S
assistant