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