(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]
PB[Black to play and kill]AW[nm][om][pm][mn][qn][rn][mo][ro][np][op][pp][qp]AB[ml][nl][ol][pl][ql][lm][rm][ln][on][lo][oo][qo][lp][mp][rp][nq][oq][pq][qq][rq]
(;B[po]C[This is atari and the correct move.]
;W[no]
;B[pn]C[Black now makes a bulky-five dead shape]
;W[nn]
;B[po]C[If white takes black just plays back at the vital point.])
(;B[no]C[This is also atari...]
;W[po]C[...but white can take a stone to make a second eye.]
(;B[mm]
;W[nn]
;B[qm]
;W[pn])
(;B[pn]
;W[nn])
(;B[qm]
;W[pn]
;B[mm]
;W[nn]))
(;B[mm]C[If black plays here white can live easiliy.]
(;W[no]
;B[po]
;W[nn]
;B[qm]
;W[pn])
(;W[po]
;B[nn]
;W[no]
;B[qm]
;W[pn])
(;W[nn]
;B[no]
;W[po]
;B[qm]
;W[pn]))
(;B[pn]C[Thisn too fails to kill.]
;W[po]
;B[mm]
;W[nn]
;B[qm]
;W[no]))
