You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
dimethyl 2,3-bis(5,5-diethyl-2-oxo-1,3,2lambda5-dioxaphosphinan-2-yl)butanedioate is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H36O10P2
assistant