Time limit: 1.00 s Memory limit: 512 MB
You and some monsters are in a labyrinth. When taking a step to some direction in the labyrinth, each monster may simultaneously take one as well. Your goal is to reach one of the boundary squares without ever sharing a square with a monster.
Your task is to find out if your goal is possible, and if it is, print a path that you can follow. Your plan has to work in any situation; even if the monsters know your path beforehand.
Input
The first input line has two integers
After this there are
Output
First print "YES" if your goal is possible, and "NO" otherwise.
If your goal is possible, also print an example of a valid path (the length of the path and its description using characters D, U, L, and R). You can print any path, as long as its length is at most
Constraints
$1 \le n,m \le 1000$
Example
Input:
5 8
########
#M..A..#
#.#.M#.#
#M#..#..
#.######
Output:
YES
5
RRDDR