We proceed by checking the difference between pairs of alternate numbers i.e., (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). Clearly, there are two such pairs.