% 20-queens:
% 15 12 10 7 13 6 8 19 11 16 20 17 4 18 9 14 2 5 3 1 
%
q = [15, 12, 10, 7, 13, 6, 8, 19, 11, 16, 20, 17, 4, 18, 9, 14, 2, 5, 3, 1];
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