We find the stable homotopy classification of elliptic operators on
stratified manifolds. Namely, we establish an isomorphism of the set of
elliptic operators modulo stable homotopy and the K-homology group of the
singular manifold. As a corollary, we obtain an explicit formula for the
obstruction of Atiyah--Bott type to making interior elliptic operators
Fredholm.Comment: 28 pages; submitted to Izvestiya Ross. Akad. Nau