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