39935

These two were the only possible solutions 8,7,13,10,6,12,9 and 6,9,11,12,4,14,7
First of all we tried all the possible two numbers that could add up to 15 from 14-1,13-2,12-3 etc.

Only two pairs of positive intergers were correct those digits were 7,8 and 6,9 they have to be this way around otherwise the answer will be incorrect.If you were to line these up opposite each other you'll notice a pattern which is +2 -2 +2 -2
1,14
2,13
3,12
4,11
5,10
6,9 one of the answers
7,8 the other solution
8,7
9,6
10,5
11,4
12,3
13,2
14,1