You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
propan-2-yl (3S)-4-[[(2R,3S,3aS,7aS)-2-(2,4-dioxopyrimidin-1-yl)-3-ethynyl-3-methyl-5-oxo-3a,4,7,7a-tetrahydro-2H-furo[3,2-d]oxaphosphinin-5-yl]oxy]-3-fluorobutanoate is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H26FN2O8P
assistant