You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-(4-bromophenyl)-2-butylsulfinyl-6-thiophen-2-ylthieno[2,3-b]pyridin-3-amine is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H19BrN2OS3
assistant