[0,1,2,3,2,3,4,5,6,3,4,5,6,7,8,9,4,5,6,7,8,9,10, 11,12,5,6,7,8,9,10,11,12,13,14,15,6,7,8,9,10,11, 12,13,14,15,16,17,18,7,8,9,10,11,12,13,14,15,16, 17,18,19,20,21]