(;AB[cs]AB[cr]AB[dq]AB[dp]AB[eq]AB[fq]AB[gq]AB[gs]AB[bn]AB[cm]AW[br]AW[bs]AW[cq]AW[cp]AW[eo]AW[do]AW[fo]AW[ho]AW[hq]AW[iq]AW[jr]AW[is]AW[gr]AB[fs]C[Black to live]AP[goproblems]
(;B[ds]
(;W[er]C[CHOICE]
(;B[bp]
(;W[bo]C[CHOICE]
(;B[bq];W[co]
(;B[aq]
(;W[ao]C[CHOICE]
(;B[fr];W[ap]
(;B[ar];W[as];B[bq]C[CHOICERIGHT])
(;B[hr];W[hs];B[ar];W[as];B[bq]C[RIGHT]))
(;B[ar];W[fr];B[hr];W[hs])
(;B[hr];W[hs]
(;B[fr];W[ap])
(;B[ar];W[fr]))
(;B[es];W[ap];B[ar];W[as];B[bq]C[RIGHT]))
(;W[fr];B[dr]
(;W[ao];B[hr];W[ap];B[ar];W[as];B[bq]C[RIGHT])
(;W[hr];B[ao]C[RIGHT])))
(;B[ar];W[ap]
(;B[as];W[fr])
(;B[aq];W[as];B[bq];W[fr]))
(;B[fr];W[aq])
(;B[ao];W[aq]))
(;B[ao];W[co];B[bq])
(;B[fr];W[bq]))
(;W[bq];B[co]C[];W[ap];B[bo];W[ar];B[fr];W[hr];B[ao];W[es];B[dr];W[hs];B[aq]C[A 4-step ko. Not a clean kill but close enough.Thanks to Zinger for pointing at this.RIGHT]))
(;B[co];W[bp];B[aq];W[ar];B[ap];W[bo])
(;B[fr];W[bo])
(;B[bq];W[bp];B[aq];W[ap])
(;B[hr];W[fr]
(;B[hs];W[ir])
(;B[es];W[hs];B[dr];W[bo])))
(;W[bo];B[er]C[RIGHT]))
(;B[er];W[ds]
(;B[dr];W[bo])
(;B[bp];W[dr]))
(;B[bp];W[dr]
(;B[co];W[ds]
(;B[bq];W[cr];B[ar];W[er];B[fr];W[hs]C[and black loses the race])
(;B[cr];W[bq]))
(;B[bq];W[co]))
(;B[es];W[dr];B[ds];W[bo])
(;B[dr];W[bo]
(;B[fr];W[es])
(;B[hr];W[hs]
(;B[es];W[fr])
(;B[fr];W[es])))
(;B[hr];W[dr])
(;B[co];W[dr])
(;B[bq];W[dr]))