You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 2-N-(4-methylphenyl)-6-[(4-phenylpiperazin-1-yl)methyl]-1,3,5-triazine-2,4-diamine by IUPAC nomenclature, provide its molecular formula.
user
C21H25N7
assistant