[0,1,1,2,2,3,3,2,2,3,3,4,4,5,5,6,6,7,7,6,6,7,7,8, 8,9,9,8,8,9,9,8,8,7,7,6,6,5,5,6,6,7,7,8,8,9,9,8,8, 9,9,10,10,11,11,12,12,11,11,12,12,13,13,14,14,15, 15,16,16,15,15,16,16,17,17,18,18,19]