EVENT
BOARDSIZE 19
SETUP W D18 F17 J17 R10 R17 Q17 P18 
SETUP B C17 D16 D14 C10 O18 P17 N17 Q16 R16 
MARK 1@P17 2@P18 3@O18
COM
Problem 71. White to play.  

Black blocks with 1 and 3. What should White do now ? 
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W 1 P16
USER
CORRECT ANSWER
ENDUSER
COM
Correct Answer.

White should cut with 1.
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  VAR
  W 1 S16
  COM
  Failure.

  If White simply plays 1 ...
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  B 2 S15
  W 3 S17
  COM
  ... and 3, ...
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  B 4 P16
  COM
  ... Black connects with 4.
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  W 5 Q18
  COM
  White lives with 5, but she ends in gote.
  <=
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  ENDVAR
B 2 O17
W 3 S16
B 4 S15
W 5 S17
B 6 R14
W 7 Q18
COM
She can then live in the corner in sente with the moves to 7.
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B 8 P15
COM
<=
ENDCOM