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