You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[(2-chloro-1,3-thiazol-5-yl)methyl]-2-(2-oxo-2-phenylmethoxyacetyl)imidazo[1,2-a]pyridin-4-ium-3-olate is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H14ClN3O4S
assistant