You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[[4-(2,5-dihydropyrrol-1-yl)phenyl]methyl]-1-ethyl-3-(3-methylsulfanylcyclohexyl)guanidine is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H32N4S
assistant