You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named [1-[(2-butyl-1H-imidazol-5-yl)methyl]piperidin-3-yl]-(3-methylthiophen-2-yl)methanone by IUPAC nomenclature, provide its molecular formula.
user
C19H27N3OS
assistant