rosagold: Currently only the first move C19 is the marked solution. I would like to make C19-E19-D19 the correct sequence. Because C19-E19-A18 actually is dead. i guess the whole problem aims more for the A18 vs D19 part, instead of finding the 1st move.
Farkas: I disagree with your comment.
A18 is obviously not good, as it is self-atari, but D19 isn't good, either, as it is unnecessary.
Currently only the first move C19 is the marked solution. I would like to make C19-E19-D19 the correct sequence. Because C19-E19-A18 actually is dead. i guess the whole problem aims more for the A18 vs D19 part, instead of finding the 1st move.