(;AB[bc]AB[bd]AB[cd]AB[dd]AB[ed]AB[fc]AB[gc]AB[gb]AB[ib]AW[fb]AW[ea]AW[ec]AW[dc]AW[cc]AW[bb]AP[goproblems]
(;B[ab];W[db];B[ba];W[ca];B[cb]C[Adv. koCHOICE])
(;B[ba];W[ab]
(;B[ca];W[cb];B[ga];W[eb];B[da]C[CHOICE])
(;B[cb];W[db];B[ca];W[da];B[ga];W[aa]C[CHOICE])
(;B[da];W[cb];B[ca];W[eb]C[CHOICE]))
(;B[ga];W[ab]
(;B[ca];W[ba]C[CHOICE])
(;B[eb];W[db];B[fa];W[eb]C[CHOICE]))
(;B[ca];W[cb]
(;B[ga];W[da]
(;B[eb];W[ba]C[CHOICE])
(;B[ab];W[ba]C[CHOICE]))
(;B[ab];W[ba];B[ga];W[da]C[CHOICE]))
(;B[db];W[cb];B[ab];W[da];B[ba]C[RIGHT]))