You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the compound with this IUPAC name 2-ethyl-1-methyl-4-pyridin-4-yl-3-(4-sulfamoylphenyl)-3H-pyrazole-5-carboxylic acid ?
user
C18H20N4O4S
assistant