Topic Portal (internal title 113)
Input Format
The first line of a positive integer $ n $.
Next $ $ n-rows, each row $ $ integers n-described $ C $ matrix. Ensure that the input is a Linxian Sen matrix.
Output Format
If not possible, then the output line Impossible $ $; otherwise, output a line containing only a $ \ {U, D, L, R \} $ string representing the sequence of a parameter $ $ Typ. Your sequence length can not exceed $ 10 ^ 6 $. If the need for any operation, the empty sequence.
Sample
Sample input 1:
2
1 2
3 0
Sample output 1:
Impossible
Sample input 2:
3
3 2 5
4 1 8
6 7 0
Sample Output 2:
UULDLU
Data range and tips
The title uses subtasks score. Only when you pass all the tests point to the next sub-task, you can get the score of the subtasks.
For all the data, $ 1 \ leqslant n \ leqslant 50 $.
$ 1 $ ($ 30 minutes $) $ n \ leqslant 3 $.
$ 2. $ ($ 30 minutes $) $ n \ leqslant 10 $.
$ 3 $ ($ 40 $ points) is not particularly limited.
answer
Stay pit