You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name N-[[3-[(4-fluorophenyl)methyl]-4,5-dihydro-1,2-oxazol-5-yl]methyl]-2-(3-methoxyphenyl)acetamide into its molecular formula.
user
C20H21FN2O3
assistant