EVENT
BOARDSIZE 19
SETUP W K16 O17 
SETUP B D16 H17 Q16 Q14 
MARK \t@K16 \t@H17
COM
Problem 2. Black to play.  

White's marked stone is high, while Black's marked stone is lying
in wait to gouge out White's base. What is the correct move for
Black ? 
ENDCOM
B 1 M17
USER
CORRECT ANSWER
ENDUSER
COM
Correct Answer.

Black 1 is a strong invasion. It is the simplest way to play.
<=
ENDCOM
  VAR
  B 1 M16
  USER
..CORRECT ANSWER
  ENDUSER
  COM
  Correct Answer.

  The high invasion of Black 1 is also correct, but it is more
  difficult.
  <=
  ENDCOM
  ENDVAR