You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-(4-ethoxybutyl)-3-[2-[2-(4-fluorophenyl)-1,3-oxazol-4-yl]ethyl]-2-methylguanidine is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H27FN4O2
assistant