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