Angle#2812
A rectangular board of size M \times N is given, with some cells removed. How many ways are there to place a "corner" of three cells on the board so that all three cells are within the board and none of them are removed?
The first line contains two integers and (1 \leq M, N \leq 100), separated by a space. Each of the next lines contains characters; the -th character in the -th line is if the cell is removed, and otherwise.
Output a single integer indicating the number of ways to place a corner on the given board.
Example 1
Example 2