p00711 Red and Black
There is a rectangular room, covered with square tiles. Each tile is colored either red or black. A man is standing on a black tile. From a tile, he can move to one of four adjacent tiles. But he can't move on red tiles, he can move only on black tiles.

Write a program to count the number of black tiles which he can reach by repeating the moves described above.



Input

The input consists of multiple data sets. A data set starts with a line containing two positive integers W and H; W and H are the numbers of tiles in the x- and y- directions, respectively. W and H are not more than 20.

There are H more lines in the data set, each of which includes W characters. Each character represents the color of a tile as follows.

* '.' - a black tile
* '#' - a red tile
* '@' - a man on a black tile(appears exactly once in a data set)


The end of the input is indicated by a line consisting of two zeros.

Output

For each data set, your program should output a line which contains the number of tiles he can reach from the initial tile (including itself).

Examples

Input

6 9
....#.
.....#
......
......
......
......
......
#@...#
.#..#.
11 9
.#.........
.#.#######.
.#.#.....#.
.#.#.###.#.
.#.#..@#.#.
.#.#####.#.
.#.......#.
.#########.
...........
11 6
..#..#..#..
..#..#..#..
..#..#..###
..#..#..#@.
..#..#..#..
..#..#..#..
7 7
..#.#..
..#.#..
###.###
...@...
###.###
..#.#..
..#.#..
0 0


Output

45
59
6
13


Input

6 9
....#.
.....#
......
......
......
......
......
@...#
.#..#.
11 9
.#.........
.#.#######.
.#.#.....#.
.#.#.###.#.
.#.#..@#.#.
.#.#####.#.
.#.......#.
.#########.
...........
11 6
..#..#..#..
..#..#..#..
..#..#..###
..#..#..#@.
..#..#..#..
..#..#..#..
7 7
..#.#..
..#.#..
.###
...@...
.###
..#.#..
..#.#..
0 0


Output

45
59
6
13
```python
from collections import deque

y = [-1,0,1,0]
x = [0,-1,0,1]

def main():

    h,w = 0,0
    c = []

    def check(i,j):
        return 0<=i and i<h and 0<=j and j<w

    def bfs(a,b):
        res = 0
        d = deque()
        d.append([a,b])
        f = [[False]*w for _ in range(h)]
        while len(d):
            i,j = d.popleft()
            if not check(i,j):continue
            if c[i][j]=='#':continue
            if f[i][j]==True:continue
            res += 1
            f[i][j]=True
            for k in range(4):
                d.append([i+y[k],j+x[k]])
        return res

    while True:
        w,h = map(int,input().split())
        if h==0 and w==0:break
        c = []
        for i in range(h):
            c.append(input())
        res = 0
        for i in range(h):
            for j in range(w):
                if c[i][j]=='@':
                    res = bfs(i,j)
        print(res)

if __name__ == '__main__':
    main()



```