You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-[(6,6-dimethyl-4-oxo-5,7-dihydro-2,1-benzoxazol-3-yl)methyl]-N-propylbenzamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H24N2O3
assistant