You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(10,19-diethyl-19-methyl-18-methylidene-14-oxo-17-oxa-3,13-diazapentacyclo[11.8.0.02,11.04,9.015,20]henicosa-1(21),2,4(9),5,7,10,15(20)-heptaen-7-yl) 4-[6-(2,5-dioxopyrrol-1-yl)hexanoyl]piperazine-1-carboxylate is the IUPAC name of a molecule. Please give its molecular formula.
user
C39H43N5O7
assistant