You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named tert-butyl 2-[(3R)-2-oxo-4-[2-oxo-2-(oxolan-2-yl)ethyl]sulfanyl-3-[(2-phenoxyacetyl)amino]azetidin-1-yl]-2-(tributyl-lambda5-phosphanylidene)acetate by IUPAC nomenclature, provide its molecular formula.
user
C35H55N2O7PS
assistant