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