You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule (E)-3-(1,3-dimethyl-2,4-dioxopyrimidin-5-yl)-N-[4-(4,6-dimethylpyrimidin-2-yl)sulfanylphenyl]prop-2-enamide .
user
C21H21N5O3S
assistant