Score : 1000 points
Snuke got a present from his mother on his birthday. The present was a pair of two sequences a and b, consisting of positive integers. They satisfied all of the following properties:
He was happy, until one day he lost both of the sequences. Now, he only remembers that the sequence a was a permutation of another sequence A of length M.
To bring him happiness again, his mother has decided to give him another pair of sequences a and b that satisfies his favorite properties and is consistent with his memory.
The input is given from Standard Input in the following format:
N M A_1 A_2 ... A_M
If there exists a pair of sequences a and b that satisfies the properties and is consistent with Snuke's memory, print three lines. The first line must contain the sequence a, the second line must contain the length of the sequence b, and the third line must contain the sequence b.
If such a pair does not exist (because Snuke's memory is wrong or some other reason), print a single line containing the word Impossible
(case-sensitive).
3 2 2 1
1 2 1 3
6 1 6
6 3 1 2 3
55 10 1 2 3 4 5 6 7 8 9 10
Impossible