(;AW[ba]AW[ac]AB[ad]AB[bd]AB[cd]AB[dc]AB[db]AB[eb]AB[ea]AW[fa]AW[fb]AW[fc]AW[ec]AW[dd]AW[de]AW[ce]AW[be]AW[ae]AP[goproblems]
(;B[bb];W[ab]
(;B[cb];W[bc];B[cc];W[ca];B[aa];W[ab];B[ac]C[RIGHT])
(;B[bc];W[cb];B[aa];W[ab]C[]))
(;B[bc];W[bb];B[ab];W[cb];B[cc];W[da];B[ca]C[Adv. ko])
(;B[cb];W[bb];B[bc]
(;W[ab]C[CHOICE])
(;W[cc])))