(;GM[1]FF[4]SZ[19]
GN[Black's correct response: no ko]
PC[https://senseis.xmp.net/?HitachiNumber121/solution]AP[GoWiki:2009]
DT[2022-10-31]
C[Diagram from https://senseis.xmp.net/?HitachiNumber121/solution

Black's correct response: no ko]
PL[B]

AB[aa][da][bb][cb][gb][bc][cc][ec][gc][dd][ed][gd][ce][cf][bg][cg]
AW[ab][db][eb][fb][dc][bd][cd][be][bf]
CR[aa][bd][cd][be][bf]

;W[ba]C[W4]MN[4]
;B[ad]C[B5]MN[5]

;CR[aa][bd][cd][be][bf]
)
