Next , We cut the handle along C, separating the handle into two pieces (see Figure 9-24b). The two resulting holes are then capped to produce a new 2-cell region in each case (see Figure 9-24c). This procedure transforms S into a surface S” of genus n-1, since the two capped pieces are part of the sphere of S”. Moreover, the vertices and edges of G’ lying on C are divided into two copies. If G” denote this new graph, then G” has order p” = p’+k+2 = p+2k+4.and size q” = q’+k+2 = q+3k+4, and r” = r’+2=r+k+2 region. Applying the inductive hypothesis to G”, we have p”- q + r” = 2 - 2(n-1), or