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