Problem B. Box ≡

Author:Michail Mirzayanov   Time limit:2 sec
Input file:box.in   Memory limit:64 Mb
Output file:box.out  

Statement

Ivan works at a factory that produces heavy machinery. He has a simple job — he knocks up wooden boxes of different sizes to pack machinery for delivery to the customers. Each box is a rectangular parallelepiped. Ivan uses six rectangular wooden pallets to make a box. Each pallet is used for one side of the box.

Joe delivers pallets for Ivan. Joe is not very smart and often makes mistakes — he brings Ivan pallets that do not fit together to make a box. But Joe does not trust Ivan. It always takes a lot of time to explain Joe that he has made a mistake.

Fortunately, Joe adores everything related to computers and sincerely believes that computers never make mistakes. Ivan has decided to use this for his own advantage. Ivan asks you to write a program that given sizes of six rectangular pallets tells whether it is possible to make a box out of them.

Input file format

Input file consists of six lines. Each line describes one pallet and contains two integer numbers w and h — width and height of the pallet in millimeters respectively.

Output file format

Write a single word `POSSIBLE' to the output file if it is possible to make a box using six given pallets for its sides. Write a single word `IMPOSSIBLE' if it is not possible to do so.

Constraints

1 ≤ w, h ≤ 10000

Sample tests

No. Input file (box.in) Output file (box.out)
1 
1345 2584
2584 683
2584 1345
683 1345
683 1345
2584 683
 
POSSIBLE
2 
1234 4567
1234 4567
4567 4321
4322 4567
4321 1234
4321 1234
 
IMPOSSIBLE
0.117s 0.017s 13