You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule sodium;(2S)-6-[[(E)-2-(1,3-benzodioxol-5-yl)ethenyl]carbamoylamino]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate ?
user
C18H18N3NaO6S
assistant