You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2R,4R)-2-amino-N-[(2,4-difluorophenyl)methyl]-6-ethyl-9-hydroxy-7,10-dioxo-6,12-diazatricyclo[6.3.1.04,12]dodeca-1(11),8-diene-11-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H20F2N4O4
assistant