(;AB[an]AB[bn]AB[cn]AB[co]AB[cp]AB[ep]AB[ar]AB[bs]AW[bo]AW[br]AW[bq]AW[bp]AW[cr]AW[dr]C[Black to kill.]AB[fr]AB[er]AB[fo]AP[goproblems]
(;B[ao];W[cs]
(;B[aq];W[ap])
(;B[ap];W[aq])
(;B[as]C[RIGHT]))
(;B[ap];W[ao]
(;B[aq];W[as]
(;B[ar];W[aq])
(;B[ds];W[cs])
(;B[cs];W[ds]))
(;B[as];W[aq])
(;B[ds];W[cs])
(;B[cs];W[ds]))
(;B[aq];W[ao]
(;B[ds];W[cs]
(;B[ap];W[as])
(;B[as];W[ap];B[ar];W[as];B[bs];W[aq]))
(;B[cs];W[ds])
(;B[as];W[cs]C[Bent-four in the corner, but white has too many liberties.]))
(;B[as];W[ao]
(;B[ds];W[aq])
(;B[cs];W[ds])
(;B[aq];W[cs]C[Bent-four in the corner, but white has too many liberties.]))
(;B[cs];W[ds]
(;B[as];W[ao])
(;B[aq];W[ao])
(;B[ap];W[ao])
(;B[ao];W[aq]))
(;B[ds];W[cs]
(;B[aq];W[ap])
(;B[as];W[aq]
(;B[ao];W[as])
(;B[as];W[ao]))
(;B[ap];W[aq])
(;B[ao];W[aq])))