Exact solution of d=1 Kazakov-Migdal induced gauge theory

We give the exact solution of the Kazakov-Migdal induced gauge model in the case of a D=1 compactified lattice with a generic number $S$ of sites and for any value of N. Due to the peculiar features of the model, the partition function that we obtain also describes the vortex-free sector of the D=1 compactified bosonic string, and it coincides in the continuum limit with the one obtained by Boulatov and Kazakov in this context.