You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N,N-dimethyl-2,3b,4,5,6,6a,7,7a-octahydro-1H-cyclopenta[a]pentalene-4-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C14H21NO
assistant