You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
9-(1H-benzimidazol-2-yl)-1,1,6,6-tetramethyl-2,3,4,5-tetrahydrochromeno[6,7-h]isoquinolin-10-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C27H27N3O2
assistant