(;
GM[1]
SZ[19]
AW[qf][od][nc][pc][qc]
AB[pj][dj][dp][pd][pp][dd][jj][kd][qd][oe][pg]
LB[nc:1][kd:2][qf:3][oe:4][qc:5][qd:6][pc:7][pg:8][od:9][me:A]
C[Problem 56. Black to play.  

White punished Black's weak move at 8 by playing 9 (Black 8 at A would have been the strongest move.). How should Black respond ? ]
;B[rd]
TE[2]
C[Correct Answer.  

Securing the side with 1 ... ]
(;W[ne];B[pf]
LB[mc:B][md:A]
C[... and 3 makes Black thick. The white stones are now vulnerable: Black can aim to attack them by peeping with A, then blocking at B. <= ]
)
(;W[pf]
LB[rd:1]
C[Variation.  

After Black 1, White might push up with 2 and ... ]
;B[of];W[qg];B[pe];W[ph];B[og];W[pi];B[oj];W[qj];B[qk];W[rk]
C[... play the sequence to 12, but ... ]
;B[rl]
C[... the two-step hane of 13 is severe. ]
;W[nh];B[rj];W[qi];B[nj];W[ni]
C[Up to 18, White is out into the center, but ... ]
;B[ri]
C[... she is left with two weak groups after Black 19 ... ]
;W[rh];B[md]
C[... and 21. <= ]
)
)