You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(4R)-5-[3-[[3-chloro-4-[5-(trifluoromethyl)pyrimidin-2-yl]pyridin-2-yl]oxymethyl]cyclobutyl]oxy-4-methylpentan-2-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H23ClF3N3O3
assistant