CSES - Counting Rooms
• Time limit: 1.00 s
• Memory limit: 512 MB
You are given a map of a building, and your task is to count the number of its rooms. The size of the map is $n \times m$ squares, and each square is either floor or wall. You can walk left, right, up, and down through the floor squares.

Input

The first input line has two integers $n$ and $m$: the height and width of the map.

Then there are $n$ lines of $m$ characters describing the map. Each character is either . (floor) or # (wall).

Output

Print one integer: the number of rooms.

Constraints
• $1 \le n,m \le 1000$
Example

Input:
5 8 ######## #..#...# ####.#.# #..#...# ########

Output:
3