You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(E)-2-isocyano-3-(5-oxo-4-oxa-12-azatricyclo[8.6.0.03,8]hexadeca-1(10),2,6,8-tetraen-15-yn-6-yl)prop-2-enenitrile The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H11N3O2
assistant