(;GM[1]FF[4]SZ[19]
GN[Approach ko]
PC[https://senseis.xmp.net/?GokyoShumyoSection1Problem33/Solution]AP[GoWiki:2009]
DT[2023-01-14]
C[Diagram from https://senseis.xmp.net/?GokyoShumyoSection1Problem33/Solution

Approach ko]
PL[B]

AB[pa][pb][oc][nd][od][pd][qd][of][pf]
AW[nb][ob][qb][lc][nc][qc][md][ne][qe][qf][ng][pg][qh]

;B[rb]C[B1]MN[1]
;W[rc]C[W2]MN[2]
;B[rd]C[B3]MN[3]
;W[sb]C[W4]MN[4]
;B[ra]C[B5]MN[5]
;W[sd]C[W6]MN[6]
;B[re]C[B7]MN[7]
;W[rf]C[W8]MN[8]
;B[se]C[B9]MN[9]
;W[qa]C[W10]MN[10]

;
)
