You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(E)-2-cyano-N-(4-ethoxyphenyl)-3-[2-(3-methylphenoxy)-4-oxopyrido[1,2-a]pyrimidin-3-yl]prop-2-enamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C27H22N4O4
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