hey guys is this problem have a key point??

this question is very very easy i will give you inputs and outputs:

IN:

30
40 20
20 40
5 20
10 12
12 10
0 0
1 1
5 5
9 8
7 7
80 103
5 9
63 7
10 1
1 10
5 9
99 1
100 101
50 100
60 30
70 80
25 69
87 56
58 12
4 99
4 98
4 95
4 0
0 4
6 9

and Out

30 10
impossible
impossible
impossible
11 1
0 0
1 0
5 0
impossible
7 0
impossible
impossible
35 28
impossible
impossible
impossible
50 49
impossible
impossible
45 15
impossible
impossible
impossible
35 23
impossible
impossible
impossible
2 2
impossible
impossible

thanks #1 ;)