EVENT
BOARDSIZE 19
SETUP W F3 D2 C2 C3 C4 C6 K3 K4 M4 M6 K6 K8 L8 N13 M14 N11 M9 N9 Q5 R4 R7 R8 R9 
SETUP B D16 D4 D5 D3 E3 E2 F4 J4 J3 J5 M7 M8 L9 L10 L12 Q16 P13 Q10 Q9 Q8 O8 P6 P5 P3 
MARK \t@L9 \t@L10 \t@L12 \t@M14 \t@N13 \t@N11 \t@N9 \t@M9
COM
Problem 20. Black to play.  

Both the black and white marked stones are floating in the center.
It is Black's move. What should he do ? 
ENDCOM
B 1 K14
USER
CORRECT ANSWER
ENDUSER
COM
Correct Answer.

Black should attack with the knight's move of 1.
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  VAR
  B 1 M16
  COM
  Failure.

  Black 1 is in the wrong direction.
  ENDCOM
  W 2 K14
  COM
  It induces White to save her stones, while leaving Black's stones
  seriously injured.
  <=
  ENDCOM
  ENDVAR
W 2 M16
COM
After the exchange of 2 ...
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B 3 K16
COM
... for Black 3, ...
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W 4 O16
COM
... White makes shape with 4. but ...
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B 5 Q17
COM
... Black secures the corner and a thick position with 5. White
is in trouble.
<=
ENDCOM