X ( 2 , 8 , 3 , 7 ) X ( 4 , 2 , 5 , 1 ) X ( 6 , 11 , 7 , 12 ) X ( 8 , 4 , 9 , 3 ) X ( 10 , 5 , 11 , 6 ) X ( 12 , 9 , 1 , 10 ) {\displaystyle X(2,8,3,7)X(4,2,5,1)X(6,11,7,12)X(8,4,9,3)X(10,5,11,6)X(12,9,1,10)}