(No. 285: Oct. 8, 2001)
Black 1 is the vital point.
If White 2, Black kills White with 3 and 5.

Elementary level: Wrong Answer
Black 1 allows White to live with 2 and 4.

Black 1 is crucial to live, and White dies.

Intermediate level: Wrong Answer
Black can live with 1, but White also lives with 2 to 6.
