You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-[[4-(2-cyanophenyl)phenyl]methyl]-2-ethylsulfanyl-6-methylthieno[3,4-d]imidazole-4-carboxylic acid is the IUPAC name of a molecule. Please give its molecular formula.
user
C23H19N3O2S2
assistant