You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (E)-3-(2-methylpyrazol-3-yl)-1-[(2S)-2-[3-(pyrimidin-2-ylamino)pyrazin-2-yl]pyrrolidin-1-yl]prop-2-en-1-one by IUPAC nomenclature, provide its molecular formula.
user
C19H20N8O
assistant