You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[3-ethyl-4-hydroxy-5-[(2-hydroxy-3-methyl-4-propylphenyl)methyl]phenyl]-2-(4-methylphenyl)acetamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C28H33NO3
assistant