(;GM[1]FF[4]AP[Drago:4.22.03]SZ[19]CA[UTF-8]AW[rr][rq][sp][qp][pp][pq][oq][or]AB[qq][qr][ro][rp][rn][qo][po][op][np][mp][mr][nr]C[Black to play and kill.]
(;B[sr]C[This incorrect]
(;W[sq]
;B[rs]C[This is a ko.])
(;W[qs]C[This way White lives.]))
(;B[qs]C[This is the correct start.];W[ps]C[This stops Black escaping to the left.];B[sr]C[Now this works.]
(;W[rs]
;B[sq]C[The three black stones are only one eye when taken and the eye on the right edge is false.])
(;W[sq]C[This is White's strongest reply.];B[so]C[However Black avoids ko by playing here.];W[ss]
;B[nq]C[White cannot now capture the three stones.])))
