(;AW[br]AW[ds]AW[es]AB[cq]AB[dq]AB[eq]AB[er]AB[fr]AB[fs]AB[gq]AB[gp]AB[fp]AB[ep]AW[do]AW[eo]AW[fo]AW[go]AW[hp]AW[ho]AW[hq]AW[hr]AW[gs]C[Black to live]AW[bq]AW[bo]AB[cp]AB[dp]AW[co]AB[bp]AW[ap]AW[bn]AP[goproblems]
(;B[cr];W[cs]
(;B[bs];W[as]
(;B[dr]
(;W[bs];B[aq]C[Well done!CHOICERIGHT])
(;W[ar];B[bs];W[cs];B[ds]C[Well done!CHOICERIGHT]))
(;B[aq]
(;W[ar];B[dr];W[ao];B[bs];W[cs];B[ds]C[Well done!RIGHT])
(;W[ao];B[dr];W[ar];B[bs];W[cs];B[ds]C[Well done!RIGHT])
(;W[bs];B[ao];W[an];B[ap]C[Well done!RIGHT]))
(;B[ar];W[aq];B[dr];W[bs])
(;B[ao];W[aq];B[dr];W[an];B[bs];W[cs];B[ds]C[Well done!RIGHT]))
(;B[dr];W[bs])
(;B[aq];W[ao]
(;B[bs];W[as];B[dr];W[ar])
(;B[dr]
(;W[ar];B[bs];W[cs];B[ds]C[Well done!RIGHT])
(;W[bs];B[ar]C[Well done!RIGHT]))
(;B[ar]
(;W[as];B[dr]
(;W[aq];B[bs];W[cs];B[ds]C[Well done!RIGHT])
(;W[bs];B[aq]C[Well done!RIGHT]))
(;W[bs];B[dr]C[RIGHT])))
(;B[ar];W[aq]
(;B[dr];W[bs])
(;B[bs];W[as];B[dr];W[bs]))
(;B[ao];W[aq]
(;B[bs];W[as];B[dr];W[an];B[bs];W[cs];B[ds]C[Well done!RIGHT])
(;B[dr];W[bs]))
(;B[as];W[bs]
(;B[aq];W[ar])
(;B[dr];W[gr])))
(;B[cs];W[cr]
(;B[dr];W[ds])
(;B[aq];W[ar]
(;B[bs];W[dr])
(;B[dr];W[ds])))
(;B[aq]
(;W[cr]
(;B[ao];W[ar]
(;B[cs];W[ap];B[dr];W[ds]C[FORCE];B[aq]C[Ko is not the best you can get])
(;B[dr]
(;W[ap];B[cs];W[ds]C[FORCE];B[aq]C[Ko is not the best you can get])
(;W[cs];B[bs];W[ap]C[Ko]))
(;B[bs]
(;W[ap]C[White can choose to fight the ko (by playing this variation) or to settle for a seki.CHOICE])
(;W[an];B[ap];W[gr];B[cs];W[as];B[cs];W[bs]C[White can choose to fight the ko or to settle for a seki (by playing this variation).CHOICE]))
(;B[ap];W[bs];B[dr];W[gr];B[cs];W[ds];B[es];W[an]C[This leads to a ko.]))
(;B[dr];W[ar];B[cs];W[ds])
(;B[bs];W[ar];B[dr];W[cs]))
(;W[ar];B[cr];W[cs];B[bs];W[as];B[dr];W[ao];B[bs];W[cs];B[ds]C[Well done!RIGHT]))
(;B[bs];W[cr]
(;B[aq];W[ar];B[dr];W[cs])
(;B[dr];W[aq]
(;B[cs];W[ds])
(;B[ar];W[ao];B[cs];W[ds])
(;B[ao];W[an];B[cs];W[ds]))
(;B[ar];W[aq]
(;B[dr];W[ao];B[cs];W[ds])
(;B[ao];W[an];B[dr];W[ao];B[cs];W[ds]))
(;B[ao];W[aq]
(;B[dr];W[an];B[cs];W[ds])
(;B[ar];W[an];B[dr];W[ao];B[cs];W[ds])))
(;B[dr];W[cs]
(;B[aq];W[ar]
(;B[cr];W[bs])
(;B[bs];W[cr]))
(;B[ar];W[gr];B[cr];W[fq])
(;B[cr];W[bs])
(;B[ao];W[aq];B[cr];W[bs])
(;B[bs];W[cr]
(;B[ar];W[as]C[Ko])
(;B[ao];W[aq])
(;B[aq];W[ar])))
(;B[ao];W[cr]
(;B[aq];W[ar]
(;B[cs];W[ap];B[dr];W[ds]C[FORCE];B[aq]C[Ko is not the best you can get])
(;B[dr]
(;W[ap];B[cs])
(;W[cs];B[bs];W[ap]C[Ko]))
(;B[bs]
(;W[ap]C[White can choose to fight the ko (by playing this variation) or to settle for a seki.CHOICE])
(;W[an];B[ap];W[gr];B[cs];W[as];B[cs];W[bs]C[White can choose to fight the ko or to settle for a seki (by playing this variation).CHOICE]))
(;B[ap];W[bs];B[dr];W[gr];B[cs];W[ds];B[es];W[an]C[This leads to a ko.]))
(;B[dr];W[aq];B[cs];W[ds])
(;B[bs];W[aq]
(;B[dr])
(;B[ar]))
(;B[ar];W[aq];B[cs];W[as];B[dr];W[ds])))