(;GM[1]FF[4]SZ[19]
GN[Main failure]
PC[http://senseis.xmp.net/?BeginnerExercise87/Solution]AP[GoWiki:2009]
DT[2014-01-15]
C[Diagram from http://senseis.xmp.net/?BeginnerExercise87/Solution

Main failure]
PL[B]

AB[ap][bp][bq][cq][dq][dr]
AW[ao][bo][co][dp][ep][aq][eq][cr][er][ds]

;B[br]C[B1]MN[1]
;W[bs]C[W2]MN[2]

;
)
