You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[(4-phenyl-1,3-thiazol-2-yl)methyl]-1-(5,6,7,8-tetrahydronaphthalen-1-yl)guanidine is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H22N4S
assistant