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