You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-(2-ethoxy-2-oxoethyl)-6-(4-hydroxy-3-methoxy-5-methylphenyl)-4-methyl-2-oxo-1,6-dihydropyrimidine-5-carboxylic acid The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H22N2O7
assistant