You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-(2,3-dihydro-1H-inden-5-yl)-2-[(5-methyl-4-propan-2-yl-1,3-thiazol-2-yl)methyl]guanidine;hydroiodide is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H25IN4S
assistant