You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[2-(3,4-dimethylphenyl)-8-methylimidazo[1,2-a]pyridin-3-yl]methyl-trimethylazanium;iodide is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H26IN3
assistant