You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
7-hydroxy-4-oxo-N-[(1-phenylcyclohexyl)methyl]-5,6,7,8-tetrahydropyrazolo[1,5-a][1,4]diazepine-2-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H26N4O3
assistant