You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Under IUPAC nomenclature, a molecule named 1-ethyl-N-[(3-fluorophenyl)methyl]-2,3-dioxo-4H-quinoxaline-6-carboxamide is given. What is its corresponding molecular formula?
user
C18H16FN3O3
assistant