You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-[(E)-C-[[(3S)-1-[(R)-carboxy-(4-hydroxyphenyl)methyl]-2-oxoazetidin-3-yl]carbamoyl]-N-hydroxycarbonimidoyl]phenolate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H16N3O7-
assistant