21,22,29,28,30,43,42,41,31,33,32,39,40,38,19,20,48,49,47,46,45,44,3,2,4,24,23,16,17,18,25,26,27,6,5,1,0,15,13,14,12,34,35,7,11,8,10,9,37,36