Figure 19 . Classes of forests that describe the extra poles. Note that we have omitted some other classes that are obviously not contributing due to symmetry reason. Green and red lines correspond to type I and type II equations, which are used to solve (cid:27) (1) in terms of component(s) of (cid:27) (2) . Poles 0 ; 1 of type-^ (cid:23) form a subclass of class A.1. The residues of poles corresponding to non-type-^ (cid:23) diagrams enclosed within a dashed rectangle cancel each