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