(;GM[1]FF[4]SZ[19]
GN[Solution]
PC[http://senseis.xmp.net/?KyuExercise7/Solution]AP[GoWiki:2009]
DT[2012-11-20]
C[Diagram from http://senseis.xmp.net/?KyuExercise7/Solution

Solution]
PL[B]

AB[cb][db][bc][ec][dd][ed][be][de][bf][cf][df]
AW[bb][eb][fb][cc][dc][fc][ad][bd][cd][fd][ce][fe][ff][bg][dg][eg][bh]
CR[bb]
LB[ca:a][cg:b]

;B[ab]C[B1]MN[1]
;W[ac]C[W2]MN[2]
;B[ba]C[B3]MN[3]
;W[aa]C[W4]MN[4]

;CR[bb]
LB[ca:a][cg:b]
)
