(;GM[1]FF[4]SZ[19]
GN[Main line]
PC[http://senseis.xmp.net/?BQM1/Solution]AP[GoWiki:2009]
DT[2009-04-22]
C[Diagram from http://senseis.xmp.net/?BQM1/Solution

Main line]
PL[B]

AB[aa][ab][bb][eb][ec][ed][be][de][ee][bf]
AW[ca][cb][ac][dc][bd][cd][dd]
CR[ac]
LB[ae:a]

;B[bc]C[B1]MN[1]
;W[ba]C[W2]MN[2]
;B[ad]C[B3]MN[3]
;W[cc]C[W4]MN[4]

;CR[ac]
LB[ae:a]
)
