(;GM[1]FF[4]SZ[19]
GN[Problem 550]
PC[http://senseis.xmp.net/?posting=5501]AP[GoWiki:2009]
DT[2009-04-22]
C[Diagram from http://senseis.xmp.net/?posting=5501

Problem 550]
PL[B]

AB[ba][ca][db][cc][dc][cd][ae][be]
AW[da][ea][eb][ac][ec][dd][ed][ce][af][bf][cf]

;B[bb]C[B1]MN[1]
;W[bd]C[W2]MN[2]
;B[ab]C[B3]MN[3]

;
)
