You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-[(6-amino-1-benzyl-2,4-dioxopyrimidin-5-yl)-ethylamino]-N-(3-cyanothiophen-2-yl)propanamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H22N6O3S
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