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