You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (1E)-4-N-(1-cyclopropylcyclopropyl)-2-methyl-1-N-(1-methylcyclopropyl)-1-(methylideneamino)-3-propan-2-ylidenepenta-1,4-diene-1,4-diamine by IUPAC nomenclature, provide its molecular formula.
user
C20H31N3
assistant