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