(;SZ[19]AB[sr][rr][qr][pq][oq][np][no][nn][nm][mq][pl][ql][rl][qp]AW[qq][rq][pp][op][oo][on][pn][qn][qo][qm][rm]C[Black to kill white](;B[ro];W[rp](;B[sp];W[so];B[sn]C[RIGHT])(;B[sn];W[rn](;B[sm];W[so])(;B[sp];W[so]C[Even if black wins the ko white cannot be killed]))(;B[sq];W[so](;B[rn];W[sn])(;B[sp];W[rn])(;B[sm];W[rn])(;B[sn];W[rn]))(;B[so];W[sp](;B[sq];W[qp];B[sm];W[sn];B[rn];W[sn]C[Snapback])(;B[sm];W[sn];B[rn];W[sn]C[Snapback])(;B[sn];W[sm]))(;B[sm];W[so])(;B[om];W[so])(;B[pm];W[so]))(;B[rp];W[ro](;B[sq];W[sn])(;B[sn];W[sp])(;B[so];W[sp](;B[sq];W[sn])(;B[sn];W[sm])))(;B[sq];W[ro](;B[rp];W[sn])(;B[sn];W[rp])(;B[so];W[rp]))(;B[sp];W[ro];B[rp];W[so])(;B[so];W[ro])(;B[sm];W[ro])(;B[sn];W[ro])(;B[om];W[rp])(;B[pm];W[rp]))