  Let R be a finite Blaschke product. We study the C*-algebra TC_R generated by
both the composition operator C_R and the Toeplitz operator T_z on the Hardy
space. We show that the simplicity of the quotient algebra OC_R by the ideal of
the compact operators can be characterized by the dynamics near the
Denjoy-Wolff point of R if the degree of R is at least two. Moreover we prove
that the degree of finite Blaschke products is a complete isomorphism invariant
for the class of OC_R such that R is a finite Blaschke product of degree at
least two and the Julia set of R is the unit circle, using the
Kirchberg-Phillips classification theorem.
