You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-[4-(5-benzylpyrimidin-2-yl)-1,4-diazepan-1-yl]-7-(1-methylpyrazol-4-yl)imidazo[1,2-a]pyrimidine is the IUPAC name of a molecule. Please give its molecular formula.
user
C26H27N9
assistant