You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 3-methyl-N-[[1-[(4-methylphenyl)methyl]imidazol-2-yl]methyl]-N-propan-2-ylbutanamide by IUPAC nomenclature, provide its molecular formula.
user
C20H29N3O
assistant