(;GM[1]FF[4]SZ[19]
GN[Forcing moves]
PC[http://senseis.xmp.net/?XuanxuanQijingProblem251/Solution]AP[GoWiki:2009]
DT[2013-04-01]
C[Diagram from http://senseis.xmp.net/?XuanxuanQijingProblem251/Solution

Forcing moves]
PL[B]

AB[an][bn][cn][dn][do][go][ho][jo][ap][dp][ep][fp][bq][cq][dq][iq][jq][lq][ar][kr]
AW[ck][bl][dl][em][gm][bo][eo][fo][gp][gq][hq][br][cr][dr][hr][bs][es]

;B[gs]C[B1]MN[1]
;W[fs]C[W2]MN[2]
;B[hs]C[B3]MN[3]
;W[ir]C[W4]MN[4]
;B[js]C[B5]MN[5]
;W[is]C[W6]MN[6]
;B[fr]C[B7]MN[7]
;W[fq]C[W8]MN[8]
;B[er]C[B9]MN[9]
;W[eq]C[W10]MN[10]

;
)
