A 3-Dimensional problem. Please flag and/or comment if there is a mistake. Also see the next problem, 22364.
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SZ[5]
C [3-Dimensional go (2x2x2)! A5, B5, A4, and B4 make up the top 2x2 layer; D5, E5, D4, and E4 (respectively) make up the bottom. Some moves are restricted due to symmetry. White to play to get the best result under Japanese rules.][FORCE]
TR [ca][cb][ac][bc][cc][dc][ec]
LB [ba:A][bb:B][eb:C]
AB [aa]
(; W [ba]; B [bb] TR [ca][cb][ac][bc][cc][dc][ec] C [Since this is 3-D go, your stone is in atari and can only be saved by playing at E5.][FORCE] SQ [ea]; W [ea]; B [eb] TR [ca][cb][ac][bc][cc][dc][ec] C [Black ataris again.][FORCE] SQ [da]; W [da]; B [db] TR [ca][cb][ac][bc][cc][dc][ec] C [White runs, but black kills anyway (White's group has no more liberties).] LB[ba:X][da:X][ea:X])
(; W [eb]; B [bb] TR [ca][cb][ac][bc][cc][dc][ec] C [If black could play D4 or E5, that would make an eye at A4 or B5. White wants to prevent this. There is only one move that prevents both.] SQ [ea][db] (; W [da] C [Correct! Seki and jigo, the best result.][RIGHT] TR [ca][cb][ac][bc][cc][dc][ec]))
(; W [bb]; B [ea] TR [ca][cb][ac][bc][cc][dc][ec] C [Correct so far. Now what?] (; W [ab]; B [db] TR [ca][cb][ac][bc][cc][dc][ec] C [Now black has an eye at D5, and white has no way to make an eye, so black wins.])(; W [ba]; B [db] TR [ca][cb][ac][bc][cc][dc][ec] C [Now black has an eye at D5, and white has no way to make an eye, so black wins.])(; W [da]; B [db] TR [ca][cb][ac][bc][cc][dc][ec] C [The stone at D5 is captured. Now black has an eye at D5, and white has no way to make an eye, so black wins.] LB [da:X])(; W [eb]; B [db] TR [ca][cb][ac][bc][cc][dc][ec] C [Now black has an eye at D5, and white has no way to make an eye, so black wins.])(; W [db] TR [ca][cb][ac][bc][cc][dc][ec] C [Seki and jigo, the best result.][RIGHT]))
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