The lower algebraic K-theory of Fuchsian groups

Let $ \Gamma $ be a cocompact Fuchsian group. We calculate the lower algebraic K-theory of the integral group ring $ {\Bbb Z} \Gamma $ and find an explicit formula for $ {\rm K}_{i}({\Bbb Z}\Gamma),\,i \le 1 $ , in terms of the lower K-groups of maximal finite cyclic subgroups of $ \Gamma $ .