(;AB[cb]AB[cc]AB[dc]AB[da]AB[ea]AB[eb]AW[bd]AW[cd]AW[dd]AW[ec]AW[fb]AW[fc]AW[fa]AW[ee]C[White to play.]AP[goproblems]
(;W[bb];B[bc]
(;W[ac];B[ab];W[aa];B[ba];W[ca]C[White takes the ko first.RIGHT])
(;W[ba];B[ab]))
(;W[ab];B[bb]
(;W[ba];B[ac];W[bc];B[aa]C[Black takes the ko first.])
(;W[bc];B[ba])
(;W[ac];B[ba]))
(;W[bc];B[bb];W[ab];B[ba])
(;W[ba];B[bb];W[ab];B[ac];W[bc];B[aa]C[Black takes the ko first.])
(;W[ac];B[bb];W[ab];B[ba]))