(;GM[1]FF[4]SZ[19]
GN[White to kill]
PC[https://senseis.xmp.net/?RTGProblem91/Solution]AP[GoWiki:2009]
DT[2022-12-13]
C[Diagram from https://senseis.xmp.net/?RTGProblem91/Solution

White to kill]
PL[W]

AB[ab][bb][db][eb][gb][cc][dc][fc][gc]
AW[ca][cb][hb][jb][ac][bc][ec][hc][bd][cd][dd][ed][hd][fe][ge]

;W[da]C[W1]MN[1]
;B[ea]C[B2]MN[2]
;W[ba]C[W3]MN[3]
;B[aa]C[B4]MN[4]

;
)
