You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
8-(4-aminophenyl)-5-methyl-N-propyl-5H-[1,3]dioxolo[4,5-g]phthalazine-6-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H22N4O3
assistant