You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule 1-[[1-(3-fluorophenyl)cyclopropyl]methyl]-2-methyl-3-[1-(2-methylpropyl)piperidin-4-yl]guanidine into molecular formula.
user
C21H33FN4
assistant