You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(5-methylthiophen-2-yl)-[(2R)-2-(piperidin-1-ylmethyl)-1,4-oxazepan-4-yl]methanone The above is the IUPAC name of a molecule. Write its molecular formula.
user
C17H26N2O2S
assistant