imc

For any three real numbers $a$, $b$, and $c$, with $b\ne c$, the operation $\otimes$ is defined by: $$\otimes (a,b,c)=\frac{a}{b-c}$$ What is $\otimes (\otimes (1,2,3),\otimes (2,3,1),\otimes (3,1,2))$?