You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
sodium;2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11-icosafluoroundecanoate is the IUPAC name of a molecule. Please give its molecular formula.
user
C11HF20NaO2
assistant