You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Name the molecular formula for the molecule established as 2-(1H-imidazol-5-ylmethyl)-5-methyl-3,4-dihydropyrimido[1,6-a]indol-1-one using the IUPAC nomenclature.
user
C16H16N4O
assistant