You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
6-(3-methoxyphenyl)-4,7-dimethyl-2-prop-2-enylpurino[7,8-a]imidazole-1,3-dione The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H19N5O3
assistant