You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[[2-(morpholin-4-ylmethyl)phenyl]methyl]-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H26N2O2S
assistant