Grid Pathfinding

You are given a grid with n rows and m columns. Each cell in the grid is either free (represented by '.') or blocked (represented by '#'). Your task is to determine whether there exists a path from the top-left corner (cell at position (0,0)) to the bottom-right corner (cell at position (n-1, m-1)) by moving only in the four cardinal directions (up, down, left, right).

Formally, given integers n and m and a grid G such that

find whether there exists a sequence of moves that starts at (0, 0) and ends at (n-1, m-1), moving only to adjacent cells that are free.

inputFormat

The input is read from standard input (stdin) and has the following format:

n m
row1
row2
... 
rown

Here, n and m are integers representing the number of rows and columns respectively, and each of the following n lines represents a row of the grid.

outputFormat

Output a single line to standard output (stdout) containing either Yes if a path exists or No otherwise.

5 5
.....
.###.
.#.#.
.#...
.....

Yes