You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule 1-methyl-3-[(5S,6S)-6-methyl-6,7,8,9-tetrahydro-5H-benzo[7]annulen-5-yl]-1-(pyrazin-2-ylmethyl)urea into molecular formula.
user
C19H24N4O
assistant