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