(;GM[1]FF[4]SZ[19]
GN[Black to play: a or b?]
PC[http://senseis.xmp.net/?DontHelpYourOpponentExercise2]AP[GoWiki:2009]
DT[2009-04-22]
C[Diagram from http://senseis.xmp.net/?DontHelpYourOpponentExercise2

Black to play: a or b?]
PL[W]

AB[pd][pk][ol][ql][qm][pn][po][qp]
AW[qj][qk][pl][om][pm][on]
LB[oi:b][nj:a]

;W[ok]C[W1]MN[1]
;B[pj]C[B2]MN[2]
;W[pi]C[W3]MN[3]
;B[oj]C[B4]MN[4]
;W[nl]C[W5]MN[5]

;LB[oi:b][nj:a]
)
