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.

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).

• $1 \le n,m \le 1000$

Print one integer: the number of rooms.