(;GM[1]FF[4]SZ[19]
GN[White can get ko]
PC[http://senseis.xmp.net/?GokyoShumyoSection5Problem20/Solution]AP[GoWiki:2009]
DT[2014-01-29]
C[Diagram from http://senseis.xmp.net/?GokyoShumyoSection5Problem20/Solution

White can get ko]
PL[B]

AB[gb][jb][dc][ec][fc][gc][hc][ic][jc][ed][be][ce][de]
AW[ea][ga][ja][db][eb][fb][hb][ib][kb][cc][kc][cd][dd][jd][kd][ee][fe][he]

;B[cb]C[B1]MN[1]
;W[bb]C[W2]MN[2]
;B[ca]C[B3]MN[3]
;W[bc]C[W4]MN[4]
;B[ba]C[B5]MN[5]
;W[aa]C[W6]MN[6]
;B[ab]C[B7]MN[7]
;W[ac]C[W8]MN[8]

;
)
