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