[2,1,4,3,6,5,8,7,9,11,10,13,12,14,15,17,16,19,18, 20,21,23,22,24,25,26,27,29,28,31,30,32,33,34,35, 37,36,38,39,41,40,43,42,44,45,47,46,48,49,50,51, 53,52,54,55,56,57,59,58,61,60,62,63,64,65,67,66, 68,69,71,70,73,72]