You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name (3R,4R)-3-[(3-fluorophenyl)methyl]-4-hydroxy-1-(1-methylimidazole-2-carbonyl)piperidine-3-carboxylic acid into its molecular formula.
user
C18H20FN3O4
assistant