We proceed by checking the difference between pairs of alternate number
ie (6, 1), (4,2), (1, 2), (2, 8) (2,7), (8 , 4) (7 , 2), (4 , 1), (2 , 5), (1 , 3), (5 , 8), (3 , 6), (8 , 2), (6 , 1), (2 , 7), (1 , 1), (7 , 4), (1 , 1), (4 , 3), (1 , 2), (3 , 8) and (2 , 6) of these the pairs with a difference of 2 are (4 , 2) and (1 , 3) 6 [4] [1] [2] 2 8 7 4 2 [1] [5] [3] 8 6 2 1 7 1 4 1 3 2 8 6
Clearly, there are two such pairs
