Boundedness of nonbirational extremal contractions

We consider K-X-negative extremal contractions f:x --> (Z,o), where X is an algebraic threefold with only epsilon-log terminal Q-factorial singulariti es and (Z, o) is a two (respectively, one)-dimensional germ. The main resul t is that K-X is 1, 2, 3,4 or 6-complementary or we have, so-called, except ional case and then the singularity (Z is an element of o) is bounded (resp ectively, the multiplicity of the central fiber f(-1)(o) is bounded).