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