X ( 3 , 27 , 4 , 26 ) X ( 4 , 20 , 5 , 19 ) X ( 5 , 13 , 6 , 12 ) X ( 9 , 3 , 10 , 2 ) X ( 10 , 26 , 11 , 25 ) X ( 11 , 19 , 12 , 18 ) X ( 15 , 9 , 16 , 8 ) X ( 16 , 2 , 17 , 1 ) X ( 17 , 25 , 18 , 24 ) X ( 21 , 15 , 22 , 14 ) X ( 22 , 8 , 23 , 7 ) X ( 23 , 1 , 24 , 30 ) X ( 27 , 21 , 28 , 20 ) X ( 28 , 14 , 29 , 13 ) X ( 29 , 7 , 30 , 6 ) {\displaystyle X(3,27,4,26)X(4,20,5,19)X(5,13,6,12)X(9,3,10,2)X(10,26,11,25)X(11,19,12,18)X(15,9,16,8)X(16,2,17,1)X(17,25,18,24)X(21,15,22,14)X(22,8,23,7)X(23,1,24,30)X(27,21,28,20)X(28,14,29,13)X(29,7,30,6)}