[0,1,2,4,3,6,5,8,7,9,10,11,12,13,14,16,15,18,17, 20,19,22,21,24,23,25,26,27,28,29,30,31,32,33,34, 36,35,38,37,40,39,42,41,44,43,46,45,48,47,49,50, 51,52,53,54,55,56,57,58,59,60,61,62,64,63,66,65, 68,67]