You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance N-[(5R,6R)-6-methyl-7-oxo-5-phenyl-4-thia-1-azabicyclo[3.2.0]heptan-6-yl]-2-phenylacetamide .
user
C20H20N2O2S
assistant