# Incompatible Crops

First Step Contest
Limits 1s, 512 MB

Did you know that certain crops cannot grow next to each other? Given the layout of a field as a grid, determine which spots are safe for new crops.

The layout of a field will be given as rows of asterisks (indicating a spot occupied by an incompatible crop) and dots (indicating a free spot).

.**...
*.....
....**


A free spot is safe only if the 4 adjacent spots (the spots immediately above, below, left, and right) are not occupied by an incompatible crop.

In the example above, there are 5 safe spots:

.**.XX
*..X..
.XX.**


## Input

The input will contain two integers $R$ ($0 < R < 25$) and $C$ ($0 < C < 25$).

This will be followed by $R$ lines, each with $C$ characters.

## Output

Print the number of free spots.

## Sample

InputOutput
6 6
****..
*****.
..*.**
.*...*
.*.**.
..**..

3