You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
5-[3-(3-chlorophenyl)-1,2,4-oxadiazol-5-yl]-4-methyl-3-(3-methylphenyl)-6-phenyl-1,6-dihydropyrimidin-2-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C26H21ClN4O2
assistant