(;GM[1]FF[4]SZ[19]
GN[Ko for Seki]
PC[https://senseis.xmp.net/?GokyoShumyoSection3Problem49/Solution]AP[GoWiki:2009]
DT[2023-01-20]
C[Diagram from https://senseis.xmp.net/?GokyoShumyoSection3Problem49/Solution

Ko for Seki]
PL[B]

AB[ea][fb][dc][fc][gc][ic][ad][bd][cd][dd][ed][gd][ce][bf][bg][ci]
AW[da][bb][cb][db][eb][bc][ec][fd][be][fe][cf][ef][cg][bh][ch]

;B[ac]C[B1]MN[1]
;W[ab]C[W2]MN[2]
;B[ba]C[B3]MN[3]
;W[fa]C[W4]MN[4]
;B[ga]C[B5]MN[5]

;
)
