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