ЛШ 2012. Олимпиада младшая ступень

Problem B. Box ≡

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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`