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