(;GM[1]FF[4]SZ[19]
GN[Black gets either a or b to kill the white group.]
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 to kill the white group.]
PL[B]

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

;B[is]C[B5]MN[5]

;LB[kq:b][hs:a]
)
