(;GM[1]FF[4]SZ[19]
GN[Black gets either a or b for the ko.]
PC[http://senseis.xmp.net/?XuanxuanQijingProblem57/Attempts]AP[GoWiki:2009]
DT[2014-07-07]
C[Diagram from http://senseis.xmp.net/?XuanxuanQijingProblem57/Attempts

Black gets either a or b for the ko.]
PL[B]

AB[ep][fp][gp][hp][ip][jp][kp][eq][dr][er][kr][ds]
AW[dn][fn][hn][jn][ln][co][mo][cq][fq][gq][iq][lq][nq][cr][fr][jr][lr][es][fs]
LB[gr:a][ir:b]

;B[hq]C[B1]MN[1]
;W[hr]C[W2]MN[2]
;B[js]C[B3]MN[3]
;W[kq]C[W4]MN[4]
;B[hs]C[B5]MN[5]

;LB[gr:a][ir:b]
)
