You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(R)-(4-ethoxy-3-methoxyphenyl)-[3-(3-fluorophenyl)-1H-1,2,4-triazol-5-yl]methanamine is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H19FN4O2
assistant