You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2S,3S)-2-amino-N-[(5-chlorothiophen-2-yl)methyl]-3-methyl-N-prop-2-enylpentanamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C14H21ClN2OS
assistant