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