Good luck.
Of the people I have shown this to on KGS, I can tell you that Tien read most of the variations in his head and only missed one when I showed him the answer. So if you can figure this out in your head, you are quite strong.
Reminds me of a quote from my blog tidbit on Cho Chikun's thoughts on the importance of calculation.
Though we think of a game as being quite a distance from calculation and life and death problems, a game will still come to a stage requiring fierce contact fights. At such time, calculating skill will be most important.
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