(;AW[rq][qq][pq][op][np][mn][mm][ml][nk][ok][pk][ql][rl][rm][qo]AB[nm][nl][ol][pl][pm][on][oo][qm][rn][qp]SZ[19]C[Black to live] (;B[po] (;W[ro]C[CHOICE] (;B[qn]C[RIGHT]) (;B[rp];W[qn])) (;W[qn]C[CHOICE] (;B[ro];W[rp] (;B[pp]C[RIGHT]) (;B[pn]TR[pp][qo]C[RIGHT Black is alive, but there is a better way. White can use either of the marked points as ko-threats.])) (;B[rp];W[ro]) (;B[pp];W[ro]) (;B[pn];W[ro]))) (;B[ro];W[po]) (;B[qn];W[po]) (;B[pp];W[po]) (;B[pn];W[po];B[ro];W[rp]) (;B[rp];W[po] (;B[pp];W[ro]) (;B[ro];W[pp])))