You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[(1S,2S,3S)-1-(methoxymethyl)-2-(4-methylphenyl)-3-(4-methylphenyl)sulfonylcyclopropyl]methanamine is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H25NO3S
assistant