[1,2,3,1,4,2,5,3,6,1,4,7,2,5,8,3,6,9,1,4,7,10,2,5, 8,11,3,6,9,1,12,4,7,10,2,13,5,8,11,3,14,6,9,1,12, 4,15,7,10,2,13,5,16,8,11,3,14,6,17,9,1,12,4,15,7, 18,10,2,13,5,16,8,19,11,3,14,6,17,9,20,1,12,4,15, 7,18,10,21,2]