You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-hydroxy-N-[[4-(4-methylphenyl)-5-pyridin-2-yl-1H-imidazol-2-yl]methyl]acetamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H18N4O2
assistant