You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named [(1R)-1-carboxy-3-[(S)-methylsulfinyl]propyl]-[(2E)-2-[(2R)-2,6-dicarboxy-2,3-dihydro-1H-pyridin-4-ylidene]ethyl]azanium by IUPAC nomenclature, provide its molecular formula.
user
C14H21N2O7S+
assistant