You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(6S,9aS)-N-[(4-fluorophenyl)methyl]-2-methyl-8-(3-methylbutyl)-4,7-dioxo-6-(3-oxobutyl)-3,6,9,9a-tetrahydropyrazino[2,1-c][1,2,4]triazine-1-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C24H34FN5O4
assistant