You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[(2S)-1-[3-[[5-chloro-6-[(5-fluoropyridin-2-yl)methoxy]pyrimidin-4-yl]oxymethyl]-1-methylcyclobutyl]oxypropan-2-yl]acetamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H26ClFN4O4
assistant