You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
6-(1,2-dihydropyridin-4-yl)-3-methyl-N-(4-methyl-2,3-dihydropyridin-6-yl)-6,7-dihydro-1H-indol-2-amine The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H24N4
assistant