You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[1-(3-chlorophenyl)ethyl]-1-(furan-2-ylmethyl)-2,5-dimethylpyrrole-3-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H21ClN2O2
assistant