You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(1S,17S,20Z,24R,26S)-26-acetyl-4,24-dihydroxy-25-oxa-16-azahexacyclo[15.7.2.01,26.02,15.05,14.07,12]hexacosa-2,4,7,9,11,14,20-heptaen-18,22-diyne-6,13-dione The above is the IUPAC name of a molecule. Write its molecular formula.
user
C26H15NO6
assistant