X ( 2 , 7 , 3 , 8 ) X ( 4 , 11 , 5 , 12 ) X ( 5 , 19 , 6 , 18 ) X ( 8 , 1 , 9 , 2 ) X ( 10 , 14 , 11 , 13 ) X ( 12 , 3 , 13 , 4 ) X ( 15 , 20 , 16 , 21 ) X ( 17 , 1 , 18 , 6 ) X ( 19 , 14 , 20 , 15 ) X ( 21 , 16 , 22 , 17 ) X ( 22 , 10 , 7 , 9 ) {\displaystyle X(2,7,3,8)X(4,11,5,12)X(5,19,6,18)X(8,1,9,2)X(10,14,11,13)X(12,3,13,4)X(15,20,16,21)X(17,1,18,6)X(19,14,20,15)X(21,16,22,17)X(22,10,7,9)}
