(;GM[1]FF[4]SZ[19]
GN[Black to move]
PC[https://senseis.xmp.net/?GokyoSeimyoVolume3Problem54/Solution]AP[GoWiki:2009]
DT[2023-02-16]
C[Diagram from https://senseis.xmp.net/?GokyoSeimyoVolume3Problem54/Solution

Black to move]
PL[B]

AB[go][bp][cp][dp][ep][fp][dq][fq][gq][dr][er][gr][bs][gs]
AW[fn][gn][bo][co][do][fo][io][ap][bq][hq][jq][br][cr][hr][ds][es][fs]

;B[aq]C[B1]MN[1]
;W[ar]C[W2]MN[2]
;B[cs]C[B3]MN[3]
;W[as]C[W4]MN[4]
;B[fr]C[B7]MN[7]

;
)
