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