(;GM[1]FF[4]AP[Drago:4.22.03]SZ[19]CA[UTF-8]AB[sr][rp][rq][qq][pq][pr][or]AW[qr][qs][rr][ro][so][qn][qp][pp][oq][nq][nr][os][lr]C[Black to play and live.]
(;B[ps]C[Black has to stop the three stones linking out, so they can try this.];W[rs]C[But White makes a dead shape and there is no eye on the right edge.])
(;B[rs]C[So Black must start with this.];W[ss]C[This is a Ko. The only way Black can live is by taking the Ko and the three stones.];B[ps]
;W[sq]C[This clearly fails for Black, so it has to be the Ko.]))
