Saiki has bought some of his favourite coffee jelly and wishes to enjoy his treats in peace and quiet.

The school is mapped as a rectangle of length and width . Using his psychic powers, Saiki has created a 2d map of the single floored school, where `X`

marks the walls and doors, `*`

represents people and `.`

represents open space. A classroom is a group of open space cells vertically or horizontally connected. A classroom is considered empty if none of the open cells are vertically or horizontally connected to a person.

Saiki wants to enjoy his treats alone, so he asks you: how many empty classrooms are there where he can enjoy his treats?

#### Constraints

#### Input Specification

The first line contains 2 non-negative integers and .

The following lines will each contain characters, representing the school.

#### Output Specification

Output the number of empty classrooms in the school.

#### Sample Input 1

```
6 10
XXXXXXXXXX
X.*.X..X.X
XX.XXXXXXX
XXXX..XXXX
*.......XX
XXXXXXXXXX
```

#### Sample Output 1

`2`

#### Explanation for Sample Output 1

4 groups of open cells exist, 2 of which do not contain people.

#### Sample Input 2

```
7 6
XXX..X
..XXX*
XXXXXX
..*...
XXXXXX
XXXXX.
......
```

#### Sample Output 2

`3`

#### Explanation for Sample Output 2

5 groups of open cells exist, 3 of which do not contain people.

## Comments