You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name (1S,5S,6S)-5-[2,3-difluoro-5-[(2-methoxypyrido[3,4-b]pyrazin-5-yl)methyl]phenyl]-5-(fluoromethyl)-2-thia-4-azabicyclo[4.1.0]hept-3-en-3-amine into its molecular formula.
user
C21H18F3N5OS
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