You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule 2,5-difluoro-N-[1-[7-[(5-methylthiophen-2-yl)methyl]-5,6,8,9-tetrahydro-[1,2,4]triazolo[4,3-d][1,4]diazepin-3-yl]ethyl]benzamide into molecular formula.
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C21H23F2N5OS
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