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