You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 2-[(2,3-difluorophenyl)methylsulfanyl]-4-[[(1R,2R)-2-hydroxycyclopentyl]amino]-8H-pteridin-7-one into its molecular formula.
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C18H17F2N5O2S
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