You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-(4-ethylpiperazin-1-yl)-2,2,3,3,4,4,5,5,6,6,7,7,7-tridecafluoroheptan-1-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C13H13F13N2O
assistant