(;GM[1]FF[4]SZ[19]
GN[Main line]
PC[http://senseis.xmp.net/?GokyoShumyoSection2Problem1/Solution]AP[GoWiki:2009]
DT[2009-04-22]
C[Diagram from http://senseis.xmp.net/?GokyoShumyoSection2Problem1/Solution

Main line]
PL[W]

AB[oa][pb][nc][oc][pc][qc][rc][rd]
AW[mb][nb][ob][mc][nd][od][pd][qd][re][qf]

;W[sd]C[W1]MN[1]
;B[rb]C[B2]MN[2]
;W[qa]C[W3]MN[3]
;B[pa]C[B4]MN[4]
;W[sc]C[W5]MN[5]
;B[sb]C[B6]MN[6]
;W[ra]C[W7]MN[7]

;
)
