Kevin golani:
How do I solve this one?

Fokafka:
It's not that hard as long as you're keeping track of your own stones and noting when they enter atari.

dgiesbrecht:
I also found this one to be the most challenging so far.

govienna:
I think this is in the wrong cathegory.. it should be EASY

Druifdan:
I found this problem to be the most difficult one in this problemset.

DGM:
An update to my prior comment, the admin didn't explain why it didn't work, but here's the flaw in my sequence. After W-F2, responding B-D1 necessitates W-E1. Then B-E5 forces W-E6. Finally, B-C4 captures the two white stones and black lives.

DGM:
There's another sequence that captures but counts as a loss. When oriented on the bottom left of the board, white to capture: W-D5, B-E2, W-F3, B-C2, W-F2. At this point black could respond D1 or E1; white captures with F1. Or black could try F1; white captures with F1.

Ischemgeek :
After w Atari the second line cutting stone, b can either descend with the O4 group or the Q2 group and both successfully capture as the S3 group doesn't suffer from a shortage of liberties.

JacobC:
There is more than one solution here. Only one variation is accepted.