(;AB[ab]AB[bc]AB[cc]AB[dc]AB[ec]AB[eb]AB[ea]AW[ba]AW[db]AW[fa]AW[fb]AW[fc]AW[fd]AW[ed]AW[dd]AW[cd]AW[bd]AW[ac]AW[ad]AP[goproblems]
(;B[bb]
(;W[ca]C[CHOICE]
(;B[cb];W[da];B[aa]C[RIGHT])
(;B[da];W[cb];B[aa]C[RIGHT])
(;B[aa]C[seki - Black can do better]))
(;W[da]
(;B[cb];W[ca];B[aa]C[RIGHT])
(;B[ca];W[cb];B[ca]C[RIGHT])
(;B[aa];W[ge];B[ca]C[RIGHT]))
(;W[cb]
(;B[ca];W[da];B[ca]C[RIGHT])
(;B[aa];W[da]C[CHOICE])
(;B[da];W[ca];B[aa]C[RIGHT]))
(;W[aa];B[ca]C[RIGHT]))
(;B[ca];W[bb]C[]
(;B[cb];W[da])
(;B[da];W[cb]))
(;B[cb];W[bb]C[])
(;B[da];W[bb]C[]))