You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(1S,5S,6S,7R)-3-[2-(1H-indol-3-yl)ethyl]-4-oxo-10-oxa-3-azatricyclo[5.2.1.01,5]dec-8-ene-6-carboxylic acid is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H18N2O4
assistant