You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[3-[(2-fluorophenyl)sulfamoyl]-4-methylphenyl]-2-thieno[2,3-d]pyrimidin-4-ylsulfanylacetamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H17FN4O3S3
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