(;GM[1]FF[4]SZ[19]
GN[Solution]
PC[http://senseis.xmp.net/?XuanxuanQijingProblem233/Solution]AP[GoWiki:2009]
DT[2013-04-01]
C[Diagram from http://senseis.xmp.net/?XuanxuanQijingProblem233/Solution

Solution]
PL[B]

AB[pn][qn][po][lp][np][op][pp][mq][qq][rq][lr][qr][qs]
AW[rl][qm][rn][qo][qp][rp][nq][oq][pq][nr][pr][ps]

;B[sp]C[B1]MN[1]
;W[ro]C[W2]MN[2]
;B[rs]C[B3]MN[3]
;W[sr]C[W4]MN[4]

;
)
