(;GM[1]FF[4]SZ[19]AP[SmartGo:0.9.0.1]CA[UTF-8]GN[202ax rmh]AB[pp][qp][rp][oq][sq][rr]AW[oo][po][qo][ro][np][nq][nr][qq][qr][rq]C[Black to play and live]
(;B[or]C[This looks like the largest eye
space but Black loses all his eyes in the corner.]
(;W[qs]
(;B[sr];W[os])
(;B[ps];W[sr];B[ss];W[rs])
(;B[ns];W[sr];B[mr];W[lq]))
(;W[ps]C[This ends in ko.];B[os];W[sr];B[ss];W[rs]))
(;B[pr]C[Filling a liberty might also be possible.];W[rs];B[sr];W[ps];B[os];W[or]
;B[qs]C[However it is also Ko.])
(;B[ps]C[This is the correct play that avoids Ko. White cannot create a living  shape.]
(;W[sr];B[ss];W[qs];B[pr])
(;W[or];B[pr])
(;W[pr];B[or];W[qs];B[os];W[sr];B[ss])))
