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