(;AB[ar]AB[bq]AB[bp]AB[dp]AB[do]AW[bs]AW[br]AW[cq]AW[dq]AB[eq]AB[er]AW[ep]AW[fp]AW[fq]AB[fo]AB[eo]AB[go]AW[fr]AW[gq]AW[hr]AW[hs]AW[gs]AB[gp]AB[hq]AB[iq]AB[ir]AW[is]AB[js]AB[jp]C[A simple problem, yet surprisingly easy to overlook in a game.]AW[oq]AW[qp]AW[mq]AP[goproblems]
(;B[dr];W[cr]
(;B[es];W[jr]
(;B[cp];W[ks]
(;B[cs];W[ds]C[A big ko.RIGHT])
(;B[aq];W[fs])
(;B[ds];W[fs];B[rp]C[NOTTHIS]))
(;B[cs];W[ds]C[2 step ko.]))
(;B[ds];W[cs])
(;B[cp];W[ds]))
(;B[jr];W[es])
(;B[kr];W[es])
(;B[es];W[dr])
(;B[ds];W[dr])
(;B[cr];W[dr])
(;B[cp];W[dr]))