[0,-1,0,-1,2,1,2,1,4,3,4,3,6,5,6,5,8,7,8,7,10,9, 10,9,12,11,12,11,14,13,14,13,16,15,16,15,18,17,18, 17,20,19,20,19,22,21,22,21,24,23,24,23,26,25,26, 25,28,27,28,27,30,29,30,29]