You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
7-[[(2E)-2-(2-amino-5-chloro-1,3-thiazol-4-yl)-2-[(1S)-1-carboxyethoxy]iminoacetyl]amino]-3-[(3-fluoropyridin-1-ium-1-yl)methyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H19ClFN6O7S2+
assistant