(;AB[ac]AB[ab]AB[db]AB[dc]AW[cc]AW[cb]AW[bb]AW[bd]AW[ad]AB[be]AB[ce]AW[dd]AW[ed]AB[cd]C[What can black do?]AW[fc]AW[gc]AP[goproblems]
(;B[ba]
(;W[ca]
(;B[ae]
(;W[aa]
(;B[bc]C[RIGHT])
(;B[da];W[bc]))
(;W[bc];B[da]C[RIGHT])
(;W[eb];B[bc]C[RIGHT])
(;W[ec];B[bc]C[RIGHT])
(;W[da];B[ea]C[RIGHT]))
(;B[da];W[aa]C[ko])
(;B[aa];W[bc])
(;B[bc];W[aa]))
(;W[bc];B[ca];W[aa];B[ab]C[RIGHT])
(;W[da];B[ea]
(;W[ca];B[bc]C[RIGHT])
(;W[bc];B[ca];W[aa];B[ab]C[RIGHT])
(;W[eb];B[ca]C[RIGHT]))
(;W[eb]
(;B[da]C[RIGHT])
(;B[ca]C[RIGHT])))
(;B[bc];W[aa])
(;B[ca];W[ba]
(;B[da];W[eb]
(;B[ae];W[ec]C[Black can do better.])
(;B[bc];W[aa])
(;B[aa];W[bc]))
(;B[ae];W[eb]
(;B[bc];W[da])
(;B[aa];W[bc])
(;B[da];W[ec]C[Black can do better.]))
(;B[bc];W[aa])
(;B[aa];W[bc]))
(;B[ae];W[eb]
(;B[ca];W[ba]
(;B[da];W[ec]C[Black can do better.])
(;B[bc];W[da]C[Black can do better.])
(;B[aa];W[bc]))
(;B[bc];W[da]C[Black can do better.])
(;B[ba];W[da]C[Black can do better.])
(;B[da];W[ec]
(;B[bc];W[ea]C[Black can do better.])
(;B[ba];W[ea]C[Black can do better.])
(;B[ca];W[ba]C[Black can do better.])))
(;B[da]
(;W[ba]
(;B[ae];W[eb]
(;B[bc];W[ea];B[aa]C[RIGHT])
(;B[aa];W[bc])
(;B[ca];W[ec]))
(;B[bc];W[aa])
(;B[aa];W[bc])
(;B[ca];W[eb]
(;B[bc];W[aa])
(;B[aa];W[bc])
(;B[ae];W[ea];B[bc];W[ec]C[Black can do better.])))
(;W[ca];B[ae]
(;W[bc];B[ba]C[RIGHT])
(;W[aa];B[bc]C[RIGHT])
(;W[eb];B[bc]C[RIGHT]))
(;W[bc];B[ba]
(;W[aa];B[ca];W[eb];B[ab];W[ec];B[ae]C[RIGHT])
(;W[ca];B[ae]C[RIGHT]))
(;W[aa];B[ba]C[RIGHT])
(;W[eb]C[CHOICE]
(;B[ae];W[ec]
(;B[bc];W[ea]C[Black can do better.])
(;B[ba];W[ea]C[Black can do better.])
(;B[ca];W[ba]C[Black can do better.]))
(;B[ba]C[RIGHT])
(;B[bc];W[aa])
(;B[ca];W[ba]
(;B[ae];W[ec])
(;B[bc];W[aa])
(;B[aa];W[bc]))
(;B[aa];W[ec]))))