Superbowl Sunday is nearly here. In order to pass the time waiting for the halftime commercials and wardrobe malfunctions, the local hackers have organized a betting pool on the game. Members place their bets on the sum of the two final scores, or on the absolute difference between the two scores. Given the winning numbers for each type of bet, can you deduce the final scores?
The first line of input contains n, the number of test cases. n lines follow, each representing a test case. Each test case gives s and d, nonnegative integers representing the sum and (absolute) difference between the two final scores.
For each test case, output a line giving the two final scores, largest first. If there are no such scores, output a line containing "impossible". Recall that football scores are always nonnegative integers.
2
40 20
20 40
30 10
impossible
This challenge is provided by the ACM International Collegiate Programming Contest.
Please log in to submit your solution.
Difficulty 

Average test runtime  0.24 
Points (changes over time)  10 
Tried by  23 users 
Solved by  17 users 
#  Name  Runtime  Points worth 

1  ,s/java/NaN/gi  0.11  19 
2  Brian  0.12  17 
3  Justin  0.13  16 
4  Irfan  0.15  14 
5  Dark  0.16  13 
6  Kristof  0.19  11 
7  Chris Danger  0.20  10 
8  Melf  0.20  10 
9  JB  0.20  10 
10  Jan  0.21  10 
11  FinnLasse  0.27  8 
12  Mac  0.30  7 
13  Sushman  0.34  6 
14  Nis  0.36  6 
15  Birger  0.37  6 
16  Eren B. Yilmaz  0.40  5 
17  IeM  0.42  5 