(;AB[ca]AB[eb]AB[ec]AB[dc]AB[cc]AB[bc]AW[ea]AW[fa]AW[fb]AW[fc]AW[fd]AW[ed]AW[cd]AW[bd]AW[ad]AW[cf]AP[goproblems]
(;B[bb];W[da]
(;B[db];W[ac];B[ab]C[RIGHT])
(;B[ac];W[db]
(;B[aa];W[cb]C[CHOICE])
(;B[cb];W[aa]C[CHOICE])))
(;B[da];W[ac]
(;B[bb]C[CHOICE])
(;B[ab];W[bb];B[ba];W[aa]C[Disadv. koCHOICE]))
(;B[ab];W[ba]
(;B[aa]
(;W[da]C[CHOICE]
(;B[db];W[cb])
(;B[cb];W[ac])
(;B[bb];W[db])
(;B[ac];W[cb]))
(;W[cb]
(;B[db];W[da])
(;B[bb])))
(;B[bb];W[da];B[db];W[cb])
(;B[da];W[cb]
(;B[bb];W[db])
(;B[aa];W[bb];B[db];W[bb])
(;B[db];W[bb];B[aa];W[bb]))
(;B[ac];W[cb])
(;B[cb];W[da])
(;B[db];W[bb]
(;B[ac];W[da])
(;B[da];W[ac])))
(;B[ba];W[ab]
(;B[bb];W[ac])
(;B[ac];W[bb];B[cb];W[da])
(;B[aa];W[bb];B[ac];W[cb])
(;B[da];W[bb]
(;B[cb];W[ac])
(;B[ac];W[cb]))
(;B[cb];W[da])
(;B[db];W[bb])))