You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name methyl (1S,10S,12R,14S,15R,16R)-13-ethylidene-11-hydroxy-16-[(Z)-hydroxyiminomethyl]-8,11-diazapentacyclo[10.3.1.110,14.01,9.02,7]heptadeca-2,4,6,8-tetraene-15-carboxylate into its molecular formula.
user
C20H21N3O4
assistant