(;GM[1]FF[4]SZ[19]
GN[Mistake at 1]
PC[http://senseis.xmp.net/?GokyoShumyoSection1Problem20b/Solution]AP[GoWiki:2009]
DT[2009-04-22]
C[Diagram from http://senseis.xmp.net/?GokyoShumyoSection1Problem20b/Solution

Mistake at 1]
PL[W]

AB[aq][bq][cq][dq][eq][er]
AW[co][bp][dp][ep][fq][hq][br][fr]

;W[es]C[W1]MN[1]
;B[ds]C[B2]MN[2]
;W[cr]C[W3]MN[3]
;B[bs]C[B4]MN[4]

;
)
