(;GM[1]FF[4]SZ[19]
GN[first attempt]
PC[http://senseis.xmp.net/?GokyoShumyoSection5Problem20/Attempts]AP[GoWiki:2009]
DT[2009-04-22]
C[Diagram from http://senseis.xmp.net/?GokyoShumyoSection5Problem20/Attempts

first attempt]
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[bc]C[B3]MN[3]
;W[ca]C[W4]MN[4]

;
)
