You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2S,11S,12R)-11-N-hydroxy-2-N-methyl-12-(2-methylpropyl)-13-oxo-1,7-diazacyclotridecane-2,11-dicarboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H34N4O4
assistant